Author: "A. Maignan" / Topic: condensed matter physics - Searchworks@Jio Institute Digital Library Search Results

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588 results on '"A. Maignan"'

1. The electronic properties of graphene nanoribbons and the offset logarithm function

Author: Sree Ram Valluri, Ken Roberts, L. Prabhat Reddy, Najeh Jisrawi, Sibibalan Jeevanandam, Aude Maignan, Pranawa C. Deshmukh, Calcul Algébrique et Symbolique, Sécurité, Systèmes Complexes, Codes et Cryptologie (CASC), Laboratoire Jean Kuntzmann (LJK), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Indian Institute of Technology Tirupati (IITT), Department of Physics, Dayananda Sagar University, Hossur Road, Bengaluru 560114, India, Physics and Astronomy Department, The University of Western Ontario (UWO), and University of Western Ontario (UWO)
Subjects: Logarithm, 02 engineering and technology, 01 natural sciences, symbols.namesake, [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], Lambert W function, 0103 physical sciences, Generalized Lambert W function, Dirac equation, Eigenvalues and eigenvectors, 010302 applied physics, Physics, Quantum finite square well, Condensed matter physics, Graphene nanoribbons, Function (mathematics), 2D materials, 021001 nanoscience & nanotechnology, Eigenvalue equations, Massless particle, Zigzag, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], symbols, 0210 nano-technology
Abstract: International audience; Graphene Nanoribbons (GN), being an important class of next-generation carbon materials, are of immense interest and find innumerable applications in diverse fields. A variation of the generalized Lambert W function, called the Offset Logarithm function, has been found to have important applications in fields such as physics, engineering and nanotechnology. We study the electronic properties of zigzag GN and use the generalized Lambert W function to study the eigenvalue equations of the massless Dirac equation applied to zigzag GN. We have studied the effects of nanoribbon width and determined the parameters that significantly affect the obtained solutions.
Published: 2022

2. Fe2Co2Nb2O9

Author: Chien-Te Chen, Antoine Maignan, Christine Martin, Françoise Damay, François Fauth, Xiao Wang, Hong-Ji Lin, Elodie Tailleur, Zhiwei Hu, Emmanuelle Suard, Liu Hao Tjeng, Maxim Mostovoy, Theory of Condensed Matter, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Groningen [Groningen], Max Planck Institute for Chemical Physics of Solids (CPfS), Max-Planck-Gesellschaft, Max Planck Institute for chemical Physics of Solids, Ministry of Science and Technology of the People’s Republic of China, Institut Laue-Langevin (ILL), and ALBA Synchrotron light source [Barcelone]
Subjects: Magnetization, Polarization density, Materials science, Magnetic moment, Condensed matter physics, Neutron diffraction, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Materials Chemistry, Antiferromagnetism, Honeycomb (geometry), General Chemistry, Néel temperature, Magnetic field
Abstract: International audience; Fe4Nb2O9 and Co4Nb2O9 are antiferromagnetic compounds belonging to the M4M′2O9 series (M = Mn, Fe, Co; M′ = Nb, Ta), whose structure (P[3 with combining macron]c1) derives from the Cr2O3 corundum one. By mixing cobalt and iron in a 1 : 1 ratio, an Fe2Co2Nb2O9 oxide has been synthesized. Its structural, magnetic and electric characterization studies confirm that its unit cell volume (V = 331.19(1) Å3), Néel temperature (TN = 58 K) and dielectric permittivity are intermediate between those of the Fe4Nb2O9 and Co4Nb2O9 end members. The neutron diffraction study evidences an Fe:Co random occupation of the (4d) Wyckoff sites. Its antiferromagnetic structure, refined in the C2/c′ magnetic space group, shows magnetic moments in the planes of the honeycomb (HC) layers of the M4M′2O9 structure, and stacked along c, as for Fe4Nb2O9 and Co4Nb2O9. However, the magnetic field induced magnetization M(H) of Fe2Co2Nb2O9 below TN differs strongly from both end members, exhibiting a sublinear dependence. A similar rounded shape of the electric polarization P(H) curve is evidenced, in marked contrast to the linear M(H) and P(H) behaviours observed below the spin-flop magnetic field for this class of linear magnetoelectric materials. As a result, Fe2Co2Nb2O9 exhibits larger P values and steeper P responses to H at low H than both Fe4Nb2O9 and Co4Nb2O9 end members. This result is explained by a microscopic model based on the Fe and Co mixed occupation. Substitutional disorder locally allows for stronger magnetoelectric couplings and its effect does not cancel on average. This chemical substitution effect opens a new route to enhance the magnetoelectric response of honeycomb antiferromagnets.
Published: 2021

3. Crystal structure and functional properties of Nd1.6Ca0.4Ni1-yCuyO4+δ as prospective cathode materials for intermediate temperature solid oxide fuel cells

Author: Elena Filonova, A. Maignan, E. Yu. Pikalova, Alexey I. Vylkov, S.M. Pikalov, and T.Yu. Maksimchuk
Subjects: Materials science, Renewable Energy, Sustainability and the Environment, Analytical chemistry, Oxide, Energy Engineering and Power Technology, chemistry.chemical_element, 02 engineering and technology, Electrolyte, Crystal structure, Conductivity, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Oxygen, Thermal expansion, 0104 chemical sciences, chemistry.chemical_compound, Tetragonal crystal system, Fuel Technology, chemistry, Orthorhombic crystal system, 0210 nano-technology
Abstract: Complex oxides Nd1.6Ca0.4Ni1-yCuyO4+δ (y = 0.0–0.4) have been prepared by a pyrolysis of glycerol-nitrate compositions. According to the X-ray diffraction analysis, the materials are single-phase up to y = 0.3 and crystallize in an orthorhombic structure (Bmab) at room temperature. High-temperature studies assert that they all undergo a phase transition from orthorhombic to tetragonal (I4/mmm) structure in a range of 300–400 °C. With Cu doping, the over-stoichiometric oxygen content δ decreases from 0.07 (y = 0.0) down to 0.00 (y = 0.3). The studies on the compact samples reveal the maximum value of total conductivity (165 S cm−1 at 420 °C) and the minimum value of the linear coefficient of thermal expansion (11.9·10−6 K−1 in a range of 400–1000 °C in air) at y = 0.2. Chemical compatibility of the Nd1.6Cа0.4Ni1-yCuyO4+δ (y = 0.0, 0.2) oxides with oxygen- and proton conducting electrolytes (Ce0.9Gd0.1O1.95, Ce0.8Sm0.2O1.9 and BaCe0.5Zr0.3Y0.1Yb0.1O3-δ) up to a temperature of 1100 °C is demonstrated.
Published: 2021

4. Sb2Te3/graphite nanocomposite: A comprehensive study of thermal conductivity

Author: V. A. Kulbachinskii, S. Janaky, Sudip Mukherjee, Gangadhar Das, Ramzy Daou, Chandrabhas Narayana, A. K. Deb, Sylvie Hébert, P. Singha, Samir Kumar Bandyopadhyay, Vladimir G. Kytin, Aritra Banerjee, Subarna Das, Antoine Maignan, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), University of Calcutta, Moscow Institute of Physics and Technology [Moscow] (MIPT), Faculty of Physics [MSU, Moscow], Lomonosov Moscow State University (MSU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Raiganj University, UGC-DAE Consortium for Scientific Research (UGC-DAE ), Bhabha Atomic Research Centre (BARC), and Government of India, Department of Atomic Energy-Government of India, Department of Atomic Energy
Subjects: Materials science, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Specific heat measurements, Condensed Matter::Materials Science, symbols.namesake, Thermal conductivity, Thermoelectric effect, lcsh:TA401-492, Graphite, ComputingMilieux_MISCELLANEOUS, Nanocomposite, Condensed matter physics, Phonon scattering, Metals and Alloys, Thermoelectric systems, 021001 nanoscience & nanotechnology, Thermoelectric materials, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, X-ray powder diffraction, Scattering rate, Raman spectroscopy, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], symbols, Phonons, lcsh:Materials of engineering and construction. Mechanics of materials, 0210 nano-technology
Abstract: International audience; Thermoelectric performance largely depends on the reduction of lattice thermal conductivity (κL). The study of the thermal conductivity (κ) of a Sb2Te3/graphite nanocomposite system demonstrates ∼40% reduction in κL with graphite incorporation. A plausible explanation of intrinsic low κL observed in Sb2Te3 based system is presented by modeling experimental specific heat (Cp) data. Raman spectroscopy measurement combined to X-Ray diffraction data confirms the presence of graphite as separate phase in the composite sample. It is found that phonon scattering dominates heat transport mechanism in the nanostructured Sb2Te3/graphite composite. Large reduction in κL is accomplished by intensifying scattering rate of phonons via various sources. Graphite introduces effective scattering sources, i.e., defects of different dimensionalities in synthesized nanocomposite sample. Furthermore, graphite mediates phonon-phonon coupling and enhances lattice anharmonicity, which causes an intrinsic scattering of phonons with all frequencies in the Sb2Te3/graphite nanocomposite sample. Dislocation density and phonon anharmonicity of the synthesized samples are estimated from in depth analysis of temperature dependent synchrotron powder diffraction and Raman spectroscopic data. κL value as low as 0.8 W m−1K−1 at 300 K, achieved with graphite dispersion in Sb2Te3 based composite system makes the present comprehensive study an interesting concept to be developed in thermoelectric materials.
Published: 2021

5. Transport and Thermoelectric Coefficients of the Co9S8 Metal: A Comparison with the Spin Polarized CoS2

Author: Antoine Maignan, Sylvie Hébert, David Berthebaud, Tristan Barbier, Oleg I. Lebedev, Valerie Pralong, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratory for Innovative Key Materials and Structures (LINK), Saint-Gobain-National Institute of Materials Science-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences et Techniques de la Réadaptation [Lyon] (ISTR), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon
Subjects: Diffraction, Materials science, Spark plasma sintering, 02 engineering and technology, Sulfides, 010402 general chemistry, Quantum mechanics, 01 natural sciences, Metal, Magnetic properties, Thermoelectric effect, [CHIM]Chemical Sciences, Ceramic, Physical and Theoretical Chemistry, Spin (physics), ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Condensed matter physics, Lattices, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, Thermal conductivity, Transmission electron microscopy, visual_art, visual_art.visual_art_medium, 0210 nano-technology, Powder diffraction
Abstract: International audience; A Co9S8 dense ceramic sintered by spark plasma sintering has been characterized by X-ray powder diffraction and transmission electron microscopy (diffraction and high resolution). This allowed magnetic, electronic, and thermal transport measurements to be made for a cubic (a = 9.927(2)Å) Co9S8 sample free of impurities and structural defects. The magnetic susceptibility and magnetic field dependence of the magnetization point toward an antiferromagnetic state, whereas the four-probe resistivity reveals a very metallic behavior with ρ300 K = 80 μΩ.cm described by a classical electron phonon model. When compared to CoS2, even if Co9S8 exhibits lower ρ values associated with the lack of ferromagnetic fluctuations existing in the former, the Co9S8 thermoelectric power factor, negative as in CoS2, is smaller, nonetheless leading to a power factor (PF) reaching PF ≈ 0.5 mW m–1 K–2 at 300 K. In Co9S8, with its low ρ going with a very high electronic part of the thermal conductivity κ, the lattice part of κ is smaller than that of CoS2 (∼2 W m–1 K–1 for Co9S8 at 300 K) suggesting that the more complex structure of Co9S8, with two different types of CoSn polyhedra, plays an important role.
Published: 2021

6. Thermoelectric properties beyond the standard Boltzmann model in oxides: A focus on the ruthenates

Author: Sylvie Hébert, Florent Pawula, Antoine Maignan, and Ramzy Daou
Subjects: Materials science, Spins, Condensed matter physics, Magnetism, Doping, Condensed Matter::Materials Science, Entropy (classical thermodynamics), symbols.namesake, Condensed Matter::Superconductivity, Seebeck coefficient, Boltzmann constant, Thermoelectric effect, symbols, Condensed Matter::Strongly Correlated Electrons, Spin-½
Abstract: Investigation into the thermoelectric properties of oxides in the last 20 years has shown that optimization of thermoelectric power depends on original parameters that cannot be simply described by Boltzmann transport equations, as the entropy part of the Seebeck coefficient (S) plays a major role. The optimization of S strongly depends on carrier doping and also on the specific orbital filling of these carriers, on the presence of electronic correlations, and on carrier spins and magnetic exchanges between them. The peculiarities observed mostly in p-type oxides are presented here, and the Seebeck coefficient in different ruthenium oxides will be discussed. In these ruthenates with different crystallographic structures and electronic and magnetic ground states, and for which spin-orbit coupling plays a major role, the Seebeck coefficient is shown to converge toward a common value at very high temperatures, which depends on the spin entropy only. This highlights the dominant role of entropy in these p-type oxides, and demonstrates how spin and magnetism can strongly affect the thermopower of oxides. Recent results have shown that apart from oxides, magnetism can also be a tuning parameter in other chalcogenides such as sulfides.
Published: 2021

7. High temperature spin-driven multiferroicity in ludwigite chromocuprate Cu 2 CrBO 5

Author: Françoise Damay, Christine Martin, François Fauth, Antoine Maignan, Jonas Sottmann, Emmanuelle Suard, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, LLB - Nouvelles frontières dans les matériaux quantiques (NFMQ), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), ALBA Synchrotron light source [Barcelone], CELLS ALBA, Barcelona 08290, Spain, Institut Laue-Langevin (ILL), ILL, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and ANR-16-CE08-0007,BORA-BORA,Oxyborates et nouveaux matériaux multifonctionnels(2016)
Subjects: Magnetic ordering, Materials science, Physics and Astronomy (miscellaneous), Multiferroics, 02 engineering and technology, engineering.material, 01 natural sciences, Magnetic susceptibility, Superexchange interactions, 0103 physical sciences, Antiferromagnetism, Cuprate, Spin (physics), Magnetic anisotropy, 010302 applied physics, Ferroelectric materials, Condensed matter physics, Crystal structure, Jahn-Teller distortion, Transition temperature, Transition metals, 021001 nanoscience & nanotechnology, Spontaneous polarization, Dielectric properties, engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Ludwigite
Abstract: International audience; We report spin-driven multiferroicity above 100 K in the ludwigite Cu(II) oxyborate Cu2CrBO5. Spontaneous polarization, which reaches 35 µC.m-2 at 5 K, appears below 120 K, concomitantly with an incommensurate antiferromagnetic order and complex magnetodielectric effects. In magnetically induced ferroelectrics, multiferroicity usually appears at low temperature, because of the competing magnetic exchanges needed to stabilize a magnetic spiral : the remarkably high transition temperature observed in Cu2CrBO5 originates from the presence of strong Cu-O-Cu magnetic super-exchange interactions, which are not weakened by Cu/Cr cationic disorder. Our result provides an important contribution to the search for high temperature spindriven multiferroics amongst low-dimensional cuprates.
Published: 2021

8. Fe4-xNixNb2O9 (x ≤ 1): Nickel impact on the magnetoelectric properties of Fe4Nb2O9

Author: Antoine Maignan, Jacqueline-Nadine Jiongo-Dongmo, Christine Martin, O.I. Lebedev, Françoise Damay, Xiao Wang, Chang-Yang Kuo, Chun-Fu Chang, Zhiwei Hu, and Liu Hao Tjeng
Subjects: General Materials Science, General Chemistry, Condensed Matter Physics
Published: 2022

9. Spin-orbit coupling and crystal-field distortions for a low-spin 3d5 state in BaCoO3

Author: Yi Ying Chin, Ku-Ding Tsuei, Christine Martin, J. Weinen, A. Maignan, C. T. Chen, Arata Tanaka, Huan Lin, D. I. Khomskii, Stefano Agrestini, Liu Hao Tjeng, Julio C. Cezar, Sylvie Hébert, Y. F. Liao, N. B. Brookes, and Zeng-Zhen Hu
Subjects: Physics, Condensed matter physics, Peierls transition, Magnetism, Mott insulator, 02 engineering and technology, Electronic structure, Spin–orbit interaction, 021001 nanoscience & nanotechnology, Coupling (probability), Magnetocrystalline anisotropy, 01 natural sciences, 0103 physical sciences, 010306 general physics, 0210 nano-technology, Spin (physics)
Abstract: We have studied the electronic structure of ${\mathrm{BaCoO}}_{3}$ using soft x-ray absorption spectroscopy at the Co ${L}_{2,3}$ and O $K$ edges, magnetic circular dichroism at the Co ${L}_{2,3}$ edges, and valence band hard x-ray photoelectron spectroscopy. The quantitative analysis of the spectra established that the Co ions are in the formal low-spin tetravalent $3{d}^{5}$ state and that the system is a negative charge transfer Mott insulator. The spin-orbit coupling also plays an important role for the magnetism of the system. At the same time, a trigonal crystal field is present with sufficient strength to bring the $3{d}^{5}$ ion away from the ${J}_{\mathrm{eff}}=1/2$ state. The sign of this crystal field is such that the ${a}_{1g}$ orbital is doubly occupied, explaining the absence of a Peierls transition in this system, which consists of chains of face-sharing ${\mathrm{CoO}}_{6}$ octahedra. Moreover, with one hole residing in ${e}_{g}^{\ensuremath{\pi}}$, the presence of an orbital moment and strong magnetocrystalline anisotropy can be understood. Yet we also infer that crystal fields with lower symmetry must be present to reproduce the measured orbital moment quantitatively, thereby suggesting the possibility for orbital ordering to occur in ${\mathrm{BaCoO}}_{3}$.
Published: 2019

10. Effect of cobalt content on the properties of quintuple perovskites Sm2Ba3Fe5-Co O15-δ

Author: Vladimir A. Cherepanov, N.E. Volkova, I.B. Golovachev, L. Ya. Gavrilova, M. Yu. Mychinko, B. Raveau, and A. Maignan
Subjects: TEMPERATURE DEPENDENCE, Materials science, PEROVSKITE, Analytical chemistry, chemistry.chemical_element, ELECTRICAL PROPERTIES, 02 engineering and technology, Conductivity, 010402 general chemistry, SEMICONDUCTORS, 01 natural sciences, Thermal expansion, Inorganic Chemistry, BARIUM COMPOUNDS, Oxidation state, Electrical resistivity and conductivity, Seebeck coefficient, POSITIVE VALUE, Materials Chemistry, IRON COMPOUNDS, COBALT, Physical and Theoretical Chemistry, COBALT CONTENT, SAMARIUM COMPOUNDS, business.industry, P TYPE CONDUCTIVITY, PARTIAL SUBSTITUTION, OXIDATION STATE, 021001 nanoscience & nanotechnology, Condensed Matter Physics, THERMAL EXPANSION, ELECTRICAL CONDUCTIVITY, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, THERMAL EXPANSION COEFFICIENTS, Semiconductor, MULTILAYER STRUCTURE, TEMPERATURE DISTRIBUTION, chemistry, Content (measure theory), Ceramics and Composites, THERMAL PROPERTIES, 0210 nano-technology, business, Cobalt
Abstract: Quintuple perovskites Sm2Ba3Fe5-xCoxO15-δ (x = 0.5, 1.0 and 1.5) have been prepared by glycerin-nitrate technique in air. The phase purity was confirmed by XRD. Partial substitution of Co for Fe decreases the oxygen content and thus the mean oxidation state of 3d-metals. It also slightly decreases the thermal expansion coefficient of oxides. Positive value of the Seebeck coefficient confirmed p-type conductivity, though the thermopower decreases as the Co content increases. The temperature dependence of electrical conductivity reveals a maximum at 550–750°С. © 2021 Elsevier Inc. Russian Foundation for Basic Research, РФФИ: 18-33-00822; Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2019-1924 The work was financially supported in parts from the Ministry of Science and Higher Education of Russian Federation [Agreement No. 075-15-2019-1924 ] and Russian Foundation for Basic Research [project No 18-33-00822 ].
Published: 2021

11. Neutron powder diffraction studies of magnetic transitions in Fe-based orthorhombic perovskites

Author: Juan Pablo Bolletta, Antoine Maignan, Christine Martin, and Raúl Ernesto Carbonio
Subjects: Inorganic Chemistry, Structural Biology, General Materials Science, Physical and Theoretical Chemistry, Condensed Matter Physics, Biochemistry
Published: 2021

12. Structural and thermoelectric properties of n-type isocubanite CuFe2S3

Author: Antoine Maignan, David Berthebaud, Raymond Frésard, Emmanuel Guilmeau, Volker Eyert, Tristan Barbier, Oleg I. Lebedev, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), French Agence Nationale de la Recherche (ANR) [ANR-10-LABX-09-01], LabEx EMC3, European Union, École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Mineralogy, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Inorganic Chemistry, Electrical resistivity and conductivity, Thermoelectric effect, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Antiferromagnetism, Pyrrhotite, Condensed matter physics, Rietveld refinement, Chalcopyrite, Cubanite, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, visual_art, engineering, visual_art.visual_art_medium, Orthorhombic crystal system, 0210 nano-technology
Abstract: International audience; An effective strategy to enhance thermoelectric performance consists of scattering phonons by point defects, such as the ones intrinsic to the n-type isocubanite CuFe2S3. In this structure, the TEM evidences a random distribution of vacancies, and copper and iron ions of the 4c and 4d sites naturally reduce the phonon lifetime. Furthermore, orthorhombic and cubic cubanite are usually found in their natural states intimately intergrown with other sulfides such as chalcopyrite (CuFeS2) and pyrrhotite (Fe7S8). We performed comprehensive studies of Rietveld analysis of X-ray diffraction, transmission electron microscopy, and thermoelectric transport measurements of the n-type isocubanite CuFe2S3, and we obtained a maximum ZT value of 0.14 at 700 K in this environmentally friendly compound. Our electronic structure calculations support the fact that chalcopyrite CuFeS2 is an antiferromagnetic insulator, together with a higher degree of covalency of sulfide compared to oxides. The weak temperature dependence of the resistivity points towards strong disorder in the 4c and 4d sites of the isocubanite.
Published: 2017

13. XBi 4 S 7 (X = Mn, Fe): New Cost‐Efficient Layered n ‐Type Thermoelectric Sulfides with Ultralow Thermal Conductivity

Author: Héloïse Willeman, Pierric Lemoine, Erik Elkaim, Thierry Le Mercier, Carmelo Prestipino, Abdelhamid Bourhim, Florian Appert, Arthur Huguenot, Bernard Malaman, Régis Gautier, Jean Juraszek, Agathe Virfeu, Antoine Maignan, Rabih Al Rahal Al Orabi, Lauriane Pautrot-d'Alençon, Emmanuel Guilmeau, Tristan Barbier, Vivian Nassif, Jean-Baptiste Labégorre, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Solvay (France), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), CRG et Grands Instruments (CRG ), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), CRG & Grands instruments (NEEL - CRG), and Central Michigan University (CMU)
Subjects: Materials science, Condensed matter physics, Phonon, sulfides, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, thermoelectric, DFT calculations, 01 natural sciences, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Biomaterials, Thermal conductivity, Thermoelectric effect, Electrochemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [CHIM]Chemical Sciences, thermal conductivity, 0210 nano-technology, phonon
Abstract: International audience; A new class of cost‐efficient n‐type thermoelectric sulfides with a layered structure is reported, namely MnBi4S7 and FeBi4S7. Theoretical calculations combined with synchrotron X‐ray/neutron diffraction analyses reveal the origin of their electronic and thermal properties. The complex low‐symmetry monoclinic crystal structure generates an electronic band structure with a mixture of heavy and light bands near the conduction band edge, as well as vibrational properties favorable for high thermoelectric performance. The low thermal conductivity can be attributed to the complex layered crystal structure and to the existence of the lone pair of electrons in Bi3+. This feature combined with the relatively high power factor lead to a figure of merit as high as 0.21 (700 K) in undoped MnBi4S7, making this material a promising n‐type candidate for low‐ and intermediate‐temperature thermoelectric applications.
Published: 2019

14. Mn2TeO6 : Complex antiferromagnetism as a consequence of the Jahn-Teller distortion

Author: Eric Elkaim, François Fauth, Bénédicte Vertruyen, Antoine Maignan, Christine Martin, Vincent Hardy, Pascal Manuel, Françoise Damay, Dmitry D. Khalyavin, and Nami Matsubara
Subjects: Physics, Condensed matter physics, Jahn–Teller effect, Inverse, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Distortion (mathematics), Magnetization, Octahedron, 0103 physical sciences, Antiferromagnetism, Condensed Matter::Strongly Correlated Electrons, Crystallite, 010306 general physics, 0210 nano-technology, Spin (physics)
Abstract: Structural and magnetic transitions in the distorted inverse trirutile $\mathrm{M}{\mathrm{n}}_{2}\mathrm{Te}{\mathrm{O}}_{6}$ have been studied between 1.5 and 300 K using magnetization, dielectric permittivity, and specific heat measurements combined with synchrotron x-ray- and neutron-diffraction techniques on polycrystalline samples. A first-order structural transition, strongly hysteretic, occurs progressively over a large temperature span and is characterized by a broad maximum peaking at 53 K in the specific heat data. This structural transition is followed by two antiferromagnetic transitions, to commensurate and incommensurate magnetic orders, at 48 and 26 K, respectively. This succession of structural and magnetic transitions is interpreted as originating from a delicate balance between Jahn-Teller distortion of $\mathrm{Mn}{\mathrm{O}}_{6}$ octahedra, rigid $\mathrm{Te}{\mathrm{O}}_{6}$ units, and their consequences on orbital and spin orderings.
Published: 2019

15. Sr 2 Fe 1+x Re 1−x O 6 double perovskites: magnetoresistance and (magneto)thermopower

Author: Oleg I. Lebedev, Christine Martin, Raúl E. Carbonio, Lucie Nataf, François Baudelet, Jonas Sottmann, Sylvie Hébert, Antoine Maignan, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire pour l'utilisation du rayonnement électromagnétique (LURE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-MENRT-Centre National de la Recherche Scientifique (CNRS), Instituto de Investigaciones en Físico Química [Córdoba] (INFIQC), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Facultad de Ciencias Químicas [Córdoba], Universidad Nacional de Córdoba [Argentina]-Universidad Nacional de Córdoba [Argentina], Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Synchrotron Soleil, DiffAbs beamline, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France (SYNCHROTRON SOLEIL, DIFFABS BEAMLINE, SAINT-AUBIN, BP 48, 91192 GIF-SUR-YVETTE CEDEX, FRANCE), and Synchrotron Soleil, DiffAbs beamline, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
Subjects: Materials science, Magnetoresistance, Absorption spectroscopy, PEROVSKITE, chemistry.chemical_element, 010402 general chemistry, 7. Clean energy, 01 natural sciences, Catalysis, THERMOPOWER, purl.org/becyt/ford/1 [https], Delocalized electron, Electrical resistivity and conductivity, Seebeck coefficient, Materials Chemistry, MAGNETORESISTANCE, [CHIM]Chemical Sciences, Perovskite (structure), Condensed matter physics, 010405 organic chemistry, Metals and Alloys, purl.org/becyt/ford/1.3 [https], General Chemistry, Rhenium, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, Ceramics and Composites, Powder diffraction
Abstract: Polycrystalline Sr2Fe1+xRe1-xO6 samples have been synthesized and structurally characterized by X-ray powder diffraction, transmission electron microscopy and X-ray absorption spectroscopy. Resistivity strongly increases with x, but a large and negative magnetoresistance persists up to x = 0.33. This is discussed considering the charge delocalization in iron and rhenium t2g orbitals. Fil: Maignan, Antoine. Ecole Nationale Superieure D'ingenieurs de Caen; Francia Fil: Martin, Christine. Ecole Nationale Superieure D'ingenieurs de Caen; Francia Fil: Lebedev, Oleg. Ecole Nationale Superieure D'ingenieurs de Caen; Francia Fil: Sottmann, Jonas. Ecole Nationale Superieure D'ingenieurs de Caen; Francia Fil: Nataf, Lucie. Soleil Synchrotron; Francia Fil: Baudelet, François. Soleil Synchrotron; Francia Fil: Hébert, Sylvie. Soleil Synchrotron; Francia Fil: Carbonio, Raul Ernesto. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina
Published: 2019

16. Two new magnetic hollandites A 1.5 Ru 6.1 Cr 1.9 O 16 (A = Sr, Ba): magnetoresistance and thermopower

Author: Florent Pawula, Sylvie Hébert, Antoine Maignan, Denis Pelloquin, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Condensed matter physics, Magnetoresistance, Magnetism, chemistry.chemical_element, 02 engineering and technology, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Ruthenium, Metal, Octahedron, chemistry, Electrical resistivity and conductivity, visual_art, Seebeck coefficient, Hollandite, Materials Chemistry, visual_art.visual_art_medium, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; The magnetic and transport properties of two hollandites, Sr1.5Ru6.1Cr1.9O16 and Ba1.5Ru6.1Cr1.9O16, crystallizing in the I4/m space group, have been investigated. The structural study shows a lack of cation ordering, and the mixed Cr and Ru occupation in the edge shared MO6 octahedra is responsible for magnetic and electrical transport properties dominated by the localized nature of the carriers, in clear contrast with the metallic and Pauli magnetism observed in ruthenium hollandites. In particular, a complex magnetic behavior together with a cluster-glass behavior and semi-conducting resistivity are observed. Interestingly, both compounds exhibit negative magneto-resistance, reaching −18.6% at 5 K and 9 T in Ba1.5Ru6.1Cr1.9O16, and −4% in Sr1.5Ru6.1Cr1.9O16. This magneto-resistance is directly associated with the variable-range hopping nature of transport and hence with the existence of localized carriers induced by the Cr for Ru substitution. In contrast, the thermopower at high temperature shows a behavior dominated by the Ru cation network, with S ∼ 30 μV K−1, consistent with those measured for other ruthenates such as SrRuO3 and CaCu3Ru4O12 quadruple perovskites, or in the KRu4O8 hollandite. The comparison of these two hollandites with the KRu4O8 hollandite enables a direct investigation of the impact of localization on the thermopower in these materials.
Published: 2019

17. Defect structure and thermochemistry of YBaCo2O6-δ

Author: Dmitry S. Tsvetkov, A. Yu. Zuev, R.E. Yagovitin, Vladimir V. Sereda, Antoine Maignan, and Anton L. Sednev-Lugovets
Subjects: Materials science, Enthalpy, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, Calorimetry, Atmospheric temperature range, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Oxygen, Endothermic process, Standard enthalpy of formation, 010406 physical chemistry, 0104 chemical sciences, Cobaltite, chemistry.chemical_compound, chemistry, Thermochemistry, Physical and Theoretical Chemistry, 0210 nano-technology, Instrumentation
Abstract: The defect structure analysis of the oxygen deficient YBaCo2O6-δ double perovskite cobaltite confirms that the model proposed earlier for RBaCo2O6-δ (R – Pr, Gd, La) holds also for YBaCo2O6-δ. In particular, a good agreement between the pO2(T, δ) model function and experimental pO2 – T – δ data is obtained for this oxide. By means of high-temperature drop calorimetry, the enthalpy increments of YBaCo2O6-δ samples with different initial oxygen contents (0.67 ≤ δ ≤ 1) were measured in air in the (1123–1273) K temperature range. The results obtained for YBaCo2O5.0 were fitted using a Maier-Kelley function. The smoothed values of Δ 298.15 T H ∘ , Cp(T), and Δ 298.15 T S ∘ were calculated for thermodynamically stable YBaCo2O5.0 in the temperature range 1150 ≤ T, K ≤ 1350. The drop calorimetric results for the metastable YBaCo2O5.33 were used to evaluate the standard enthalpy of its reduction at 298.15 K, Δ H r e d ∘ , as (161 ± 15) kJ·(mol O2)-1 (expanded uncertainty with ≈0.95 level of confidence), which is significantly less endothermic than Δ H r e d ∘ of some other double perovskite cobaltites, RBaCo2O6-δ (R – Pr, Gd), within similar oxygen nonstoichiometry ranges (0.5 ≤ δ ≤ 1.0).
Published: 2021

18. Defect structure and redox energetics of NdBaCo2O6-δ

Author: Dmitry Malyshkin, I.L. Ivanov, Andrey Yu. Zuev, Dmitry S. Tsvetkov, Vladimir V. Sereda, Roman E. Yagovitin, and Antoine Maignan
Subjects: Materials science, Enthalpy, Analytical chemistry, Oxide, chemistry.chemical_element, 02 engineering and technology, General Chemistry, Partial pressure, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Oxygen, Redox, Standard enthalpy of formation, 0104 chemical sciences, Thermogravimetry, chemistry.chemical_compound, chemistry, General Materials Science, 0210 nano-technology, Cobalt
Abstract: The oxygen content in the double perovskite NdBaCo2O6-δ was measured as a function of oxygen partial pressure (1–10−5 atm) at different temperatures (623–1323 K) using thermogravimetry analysis (TG) and coulometric titration technique. The defect structure model of the oxide studied was proposed and successfully verified using the pO2 – T – δ data, yielding the enthalpies and entropies of the defect reactions involved. Standard enthalpy of formation from elements ( Δ f H 298 ∘ ) was measured for quenched NdBaCo2O6-δ samples with different oxygen content. Regarding the Δ f H 298 ∘ (6-δ) dependences, two important observations were made. First, the Δ f H 298 ∘ (6-δ) consists of two linear fragments with different slopes reflecting different modes of oxygen exchange, accompanied by either reduction of cobalt from Co+3 to Co+2 or from Co+4 to Co+3 in the ranges 5.0 ≤ 6-δ ≤5.5 and 5.5 Δ f H 298 ∘ (6-δ) values and those calculated using the partial molar enthalpy of oxygen, which was evaluated using the defect structure model, agree well with each other. This can be regarded as an independent verification of both the model and the related defect reaction thermodynamics.
Published: 2021

19. Structural and magnetic characterization of barbosalite Fe3(PO4)2(OH)2

Author: Jérôme Rouquette, E. Elkaïm, Sylvie Malo, A. Maignan, Christine Martin, Françoise Damay, V. Ranieri, Maria Poienar, Julien Haines, National Institute for Research and Development in Electrochemistry and Condensed Matter (NIRDElCM), LLB - Nouvelles frontières dans les matériaux quantiques (NFMQ), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Diffraction, Materials science, 02 engineering and technology, Crystal structure, 010402 general chemistry, 01 natural sciences, Hydrothermal circulation, Inorganic Chemistry, Barbosalite, Materials Chemistry, [CHIM]Chemical Sciences, Multiferroics, Physical and Theoretical Chemistry, Magnetic order, Magnetic structure, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Crystallography, Octahedron, Transmission electron microscopy, Ceramics and Composites, Crystallite, 0210 nano-technology
Abstract: International audience; Single crystals and polycrystalline samples of barbosalite Fe3(PO4)2(OH)2 iron phosphate were successfully synthesized by hydrothermal method at low pressure and temperature. Careful investigations of the crystal structure by high resolution X-ray diffraction and transmission electron microscopy evidence a complex barbosalite framework where trimers of face sharing FeO6 octahedra along the direction are connected by an additional Fe site, partly occupied. Despite this structural disorder, the spins order in a rather simple magnetic structure below 160 K. The corresponding magnetic point group of P21 makes the barbosalite a promising candidate for the design of new multiferroics.
Published: 2020

20. Lack of linear magnetoelectric effect in ferrimagnetic distorted honeycomb Ni4Nb2O9

Author: Elodie Tailleur, Françoise Damay, François Fauth, Antoine Maignan, Christine Martin, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and ALBA Synchrotron light source [Barcelone]
Subjects: 010302 applied physics, Materials science, Condensed matter physics, Neutron diffraction, Magnetoelectric effect, General Physics and Astronomy, 02 engineering and technology, Dielectric, Crystal structure, 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetization, Ferrimagnetism, 0103 physical sciences, Orthorhombic crystal system, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Ground state, ComputingMilieux_MISCELLANEOUS
Abstract: M4A2O9 transition metal oxides, with M a divalent cation and A Nb or Ta, that exhibit a structure derived from corundum constitute an interesting class of materials due to their possible magnetoelectric properties. The lack of a linear magnetoelectric effect in Ni4Nb2O9, unlike Mn4Nb2O9 or Co4Nb2O9, is explained by a comprehensive investigation, combining synchrotron x-ray and neutron diffraction with magnetization, dielectric, and polarization measurements. The m′m′m magnetic point group associated with the Pb′cn′ ferrimagnetic structure induced below 76 K by the orthorhombic Pbcn structure of Ni4Nb2O9 forbids indeed such an effect. The crystal structure and magnetic ground state of Ni4Nb2O9 are discussed and compared with those of magnetoelectric P 3 ¯ c 1 M 4 A 2 O 9 compounds whose structure derives from corundum.M4A2O9 transition metal oxides, with M a divalent cation and A Nb or Ta, that exhibit a structure derived from corundum constitute an interesting class of materials due to their possible magnetoelectric properties. The lack of a linear magnetoelectric effect in Ni4Nb2O9, unlike Mn4Nb2O9 or Co4Nb2O9, is explained by a comprehensive investigation, combining synchrotron x-ray and neutron diffraction with magnetization, dielectric, and polarization measurements. The m′m′m magnetic point group associated with the Pb′cn′ ferrimagnetic structure induced below 76 K by the orthorhombic Pbcn structure of Ni4Nb2O9 forbids indeed such an effect. The crystal structure and magnetic ground state of Ni4Nb2O9 are discussed and compared with those of magnetoelectric P 3 ¯ c 1 M 4 A 2 O 9 compounds whose structure derives from corundum.
Published: 2020

21. Mechanochemical synthesis of iodine-substituted BiCuOS

Author: Emmanuel Guilmeau, Jacinthe Gamon, Antoine Maignan, Philippe Barboux, S. Haller, T. Le Mercier, Institut de Recherche de Chimie Paris (IRCP), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), Solvay (France), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, Inorganic chemistry, chemistry.chemical_element, 02 engineering and technology, Photovoltaic effect, 010402 general chemistry, 01 natural sciences, 7. Clean energy, [SPI.MAT]Engineering Sciences [physics]/Materials, Inorganic Chemistry, Electrical resistivity and conductivity, Vacancy defect, Seebeck coefficient, Charge carrier concentration, Materials Chemistry, Semiconductor doping, Oxysulfide, Physical and Theoretical Chemistry, Mechanochemistry, Doping, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Copper, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Photovoltaic absorber, chemistry, Halogen, Ceramics and Composites, Charge carrier, 0210 nano-technology
Abstract: International audience; In the present study, we have investigated the mechanochemical synthesis method as a versatile tool to study the substitution of iodine for sulfur in the BiCuOS structure. Solid solutions with the composition BiCu1-delta OS1-xIx have been obtained up to x = 0.30. In terms of transport properties, the substitution of sulfur for iodine does not affect the bandgap but decreases the charge carrier concentration by n-type doping, as observed from the increase in the electrical resistivity and Seebeck coefficient. The effect of iodine substitution on the copper vacancy concentration delta is also addressed. This study evidences the effective tuning of the optoelectronic properties of BiCuOS with the aim of further integration into optoelectronic devices. Decrease of the charge carrier density with the iodine content in the BiCu1-delta OS1-xIx series in order to meet solar cell requirements.
Published: 2018

22. Reversed exchange-bias effect associated with magnetization reversal in the weak ferrimagnet LuFe0.5Cr0.5O3

Author: A. Szewczyk, A. Maignan, M. U. Gutowska, A. S. Moskvin, P. Iwanowski, G. Gorodetsky, Raúl E. Carbonio, A. Wisniewski, Roman Puzniak, V. Markovich, I. M. Fita, and C. Martin
Subjects: Physics, Magnetic moment, Condensed matter physics, Magnetization reversal, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Orientation (vector space), Magnetization, Exchange bias, Sign reversal, Ferromagnetism, Ferrimagnetism, 0103 physical sciences, 010306 general physics, 0210 nano-technology
Abstract: The exchange-bias (EB) effect with sign reversal was found in $\mathrm{LuF}{\mathrm{e}}_{0.5}\mathrm{C}{\mathrm{r}}_{0.5}{\mathrm{O}}_{3}$ ferrite-chromite, which is a weak ferrimagnet below ${T}_{\mathrm{N}}=265\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, exhibiting antiparallel orientation of the ferromagnetic (FM) moments of the Fe and Cr sublattices due to opposite sign of the Fe-Cr Dzyaloshinskii vector, as compared to that of the Fe-Fe and Cr-Cr. The weak FM moments of the studied compound compensate each other at temperature ${T}_{\mathrm{comp}}=230\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, leading to the net magnetic moment reversal and to observed negative magnetization, at moderate applied fields, below ${T}_{\mathrm{comp}}$. Both vertical and horizontal shifts from the origin were gotten in the field-cooled magnetization hysteresis loops. The EB sign was found to be positive below ${T}_{\mathrm{comp}}$ and negative above ${T}_{\mathrm{comp}}$, with nonmonotonic dependence on cooling field ${H}_{\mathrm{cool}}$. It sharply increases at small values of magnetic fields up to ${H}_{\mathrm{cool}}\ensuremath{\sim}1\phantom{\rule{0.16em}{0ex}}\mathrm{kOe}$, then remains almost unchanged in the range 1--30 kOe and strongly decreases with further increase of ${H}_{\mathrm{cool}}$. This unusual behavior results from the competition of various Dzyaloshinskii-Moriya interactions between $\mathrm{F}{\mathrm{e}}^{3+}$ and $\mathrm{C}{\mathrm{r}}^{3+}$ ions.
Published: 2018

23. Electronic Band Structure Engineering and Enhanced Thermoelectric Transport Properties in Pb-Doped BiCuOS Oxysulfide

Author: Rabih Al Rahal Al Orabi, Lauriane Pautrot-d'Alençon, Philippe Barboux, Jean-Baptiste Labégorre, Emmanuel Guilmeau, David Berthebaud, Thierry Le Mercier, Jacinthe Gamon, Agathe Virfeu, Antoine Maignan, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Solvay (France), Central Michigan University (CMU), Institut de Recherche de Chimie Paris (IRCP), Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC)
Subjects: Materials science, General Chemical Engineering, Carrier dynamics, 02 engineering and technology, Electronic structure, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, symbols.namesake, Electrical resistivity and conductivity, Seebeck coefficient, Materials Chemistry, Electrical conductivity, Electronic band structure, Condensed matter physics, Fermi level, Doping, General Chemistry, Lattices, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Thermal conductivity, symbols, Phonons, Density functional theory, Charge carrier, 0210 nano-technology
Abstract: International audience; In this paper, Bi1-xPbxCuOS samples (0
Published: 2018

24. Phonon Scattering and Electron Doping by 2D Structural Defects in In/ZnO

Author: Lauriane Pautrot-d'Alençon, Emmanuel Guilmeau, Mateja Košir, Thierry Le Mercier, Cédric Bourgès, Slavko Bernik, Aleksander Rečnik, Antoine Maignan, Jean-Baptiste Labégorre, Oleg I. Lebedev, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Jozef Stefan Institute [Ljubljana] (IJS), Solvay (France), Solvay Chemical company, Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, ceramic, Electron doping, 02 engineering and technology, 010402 general chemistry, thermoelectric, 01 natural sciences, Indium, [SPI.MAT]Engineering Sciences [physics]/Materials, transport properties, Thermoelectric effect, General Materials Science, Ceramic, Phonon scattering, Condensed matter physics, inversion domain boundary (IDB), Oxides, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Thermal conductivity, visual_art, visual_art.visual_art_medium, ZnO, Grain, Defects, 0210 nano-technology
Abstract: International audience; In/ZnO bulk compounds have been synthesized using a simple solid-state process. In this study, both the structural features and thermoelectric properties of the Zn1-xInxO series with ultralow indium content (0
Published: 2018

25. Coupled dielectric permittivity and magnetic susceptibility in the insulating antiferromagnet Ba2FeSbSe5

Author: David Berthebaud, Antoine Maignan, Franck Gascoin, Stefan A. Maier, C. Moussa, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Agence Nationale de la Recherche (ANR) through the program 'Investissements d'Avenir' [ANR-10-LABX-09-01], LabEx EMC3, Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Physics and Astronomy (miscellaneous), Condensed matter physics, Spins, Dielectric permittivity, Physics::Optics, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetic susceptibility, [SPI.MAT]Engineering Sciences [physics]/Materials, Electric dipole moment, Coupling (physics), Condensed Matter::Materials Science, Thermal conductivity, 0103 physical sciences, Antiferromagnetism, Condensed Matter::Strongly Correlated Electrons, 010306 general physics, 0210 nano-technology, Néel temperature
Abstract: International audience; We report on coupled changes in the dielectric permittivity and the magnetic susceptibility in the insulating antiferromagnet Ba2FeSbSe5. The real part of the dielectric permittivity (epsilon') and the thermal conductivity (kappa) shows pronounced anomalies at the Neel temperature (T-N). Our findings show that there is a weak coupling between electric dipoles and magnetic spins, which is mediated by spin-lattice coupling possibly through exchange striction effects. Published by AIP Publishing.
Published: 2018

26. Advantage of low-temperature hydrothermal synthesis to grow stoichiometric crednerite crystals

Author: Oleg I. Lebedev, Christine Martin, Antoine Maignan, Maria Poienar, National Institute for Research and Development in Electrochemistry and Condensed Matter (NIRDElCM), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Romanian National Authority for Scientific Research and Innovation, CNCS - UEFISCDI [PN-II-RU-TE-2014-4-2179], Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Metal, chemistry.chemical_compound, Flux (metallurgy), Antiferromagnetism, Hydrothermal synthesis, General Materials Science, Cationic polymerization, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Structural and magnetic properties, 0104 chemical sciences, Chemical engineering, chemistry, visual_art, visual_art.visual_art_medium, Composition (visual arts), Crednerite, 0210 nano-technology, Ethylene glycol, Stoichiometry
Abstract: International audience; This work reports a new approach for the growth of stoichiometric crednerite CuMnO2 crystals. The hydrothermal reaction, starting from soluble metal sulphates as precursors, is assisted by ethylene glycol and the formation of crednerite is found to depend strongly on pH and temperature. This method allows obtaining small hexagonal platelets with the larger dimension about 1.0-1.5 mu m and with a composition characterized by a Cu/Mn ratio of 1. Thus, these crystals differ from the needle-like millimetric ones obtained by the flux technique for which the composition departs from the expected one and is close to Cu1.04Mn0.96. This monitoring of the cationic composition in crednerite, using hydrothermal synthesis, is important as the Cu/Mn ratio controls the low temperature antiferromagnetic ground-state. (C) 2018 Elsevier Masson SAS. All rights reserved.
Published: 2018

27. Magnetothermopower and giant magnetoresistance in the spin-glass CuCrTiS4 thiospinel

Author: Antoine Maignan, Oleg I. Lebedev, Sylvie Hébert, David Berthebaud, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), French Agence Nationale de la Recherche (ANR), through the program 'Investissements d'Avenir' [ANR-10-LABX-09-01], Labex EMC3, la Region Normandie, Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, Spin glass, Condensed matter physics, Spins, Transition temperature, General Physics and Astronomy, Giant magnetoresistance, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Variable-range hopping, 0104 chemical sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Paramagnetism, Seebeck coefficient, Brillouin and Langevin functions, 0210 nano-technology
Abstract: International audience; The transport properties of the thiospinel CuCrTiS4 have been investigated in detail, focusing on the possible interplay between charges and spins, and its consequence on transport, and more specifically on the thermoelectric properties. The chemical homogeneity of a CuCrTiS4 polycrystalline sample synthesized by a direct reaction of the constitutive elements has been carefully probed by X-ray diffraction and transmission electron microscopy techniques. This thiospinel exhibits below 75 K, in its paramagnetic regime, a variable range hopping (VRH) conduction, associated with a giant magnetoresistance (MR), which persists below the spin-glass transition temperature at 8K, reaching -95% in 9 T at 5K. All the MR data can be rescaled as a function of H/T and described using a Brillouin function with S = 3/2. This demonstrates that the paramagnetic fluctuations strongly impact the transport properties, and this is confirmed by the Seebeck coefficient which depends on the magnetic field at low temperature, with a large negative magnetothermopower (MTEP) effect of -26% at 20 K, i.e., the thermopower is reduced as the spin alignment reduces the spin entropy. This first report of MTEP in CuCrTiS4 shows that this thiospinel behaves rather similarly to strongly correlated oxides, with MR and MTEP enhanced in the case of VRH transport with paramagnetic spins, such as in cobalt misfits or colossal MR manganites. Published by AIP Publishing.
Published: 2018

28. Cation order imaging and magnetic properties in the Ca2Fe2-xGaxO5 brownmillerite (0 <= x <= 1)

Author: L. Monnier, A. Maignan, C. Moussa, Denis Pelloquin, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), French Agence Nationale de le Recherche (ANR) through the Labex program EMC3, ITEM project, Norman IRMA Research Federation [FR3095], École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, Brownmillerite, 02 engineering and technology, Crystal structure, engineering.material, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Inorganic Chemistry, Magnetization, Magnetic properties, Materials Chemistry, Physical and Theoretical Chemistry, Spin (physics), Ionic radius, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Polarization density, Crystallography, Ceramics and Composites, engineering, Diamagnetism, Crystallite, 0210 nano-technology, Spin flop transition, Cation order imaging by STEM-HAADF
Abstract: International audience; Polycrystalline Ca2Fe2-xGaxO5 brownmillerite samples of nominal x = 0.5, 0.7, 0.9 and 1 compositions have been synthesized by solid state reaction under normal pressure conditions. Whatever x is, room temperature structural analyses by Rietveld refinements and electron microscopy techniques highlight a centrosymmetric Prima space group. Furthermore, STEM-HAADF observations point towards a preferential Ga occupation at the tetrahedral sites of the structure in agreement with the Rietveld analyses. This structure remains unchanged up to 1000 K as shown by thermo-diffraction analysis. As the Ga content x increases, the room temperature unit cell volume decreases gradually consistently with the fourfold coordination of the smallest Ga3+ ionic radius than that of high spin Fe3+ in the same tetrahedral coordination. This magnetic dilution by a diamagnetic cation is responsible for the T-N decrease revealed by magnetization measurements and allows a spin flop transition to be observed. Despite their similarities with the Ca2Fe2-xAlxO5 samples, no electric polarization could be evidenced for the homologous Ca2Fe2-xGaxO5 series.
Published: 2018

29. Crystal and electronic structures of two new iron selenides: Ba4Fe3Se10 and BaFe2Se4

Author: Janusz Tobola, Denis Pelloquin, David Berthebaud, Antoine Maignan, Olivier Perez, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), AGH University of Science and Technology [Krakow, PL] (AGH UST), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), and Faculty of Physics and Applied Computer Science (AGH)
Subjects: Materials science, Iron, 02 engineering and technology, Type (model theory), 010402 general chemistry, 01 natural sciences, Inorganic Chemistry, Crystal, Tetragonal crystal system, chemistry.chemical_compound, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Selenide, ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, Electronic calculations, Electron microscopy, [CHIM.CRIS]Chemical Sciences/Cristallography, Materials Chemistry, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Projection (relational algebra), Crystallography, chemistry, X-ray crystallography, Ceramics and Composites, Single crystals, 0210 nano-technology, Ternary operation, MathematicsofComputing_DISCRETEMATHEMATICS, Monoclinic crystal system
Abstract: The new ternary selenides, Ba{sub 4}Fe{sub 3}Se{sub 10} and BaFe{sub 2}Se{sub 4,} were synthesized from a reaction of appropriate amounts of elements at high temperature in a silica sealed tube, and their structures were resolved using X-ray single crystal diffraction. BaFe{sub 2}Se{sub 4} crystallizes in the tetragonal space group I4/m with a=8.008(9) A and c=5.483(3) A as cell parameters. It is a new compound with a structure isotypical to the sulfide BaFe{sub 2}S{sub 4} which belongs to the infinitely adaptive structures series Ba{sub 1+x}Fe{sub 2}S{sub 4}. The second compound, Ba{sub 4}Fe{sub 3}Se{sub 10}, crystallizes in the monoclinic space group P2{sub 1}/n with a=8.8593(1) A, b=8.8073(1) A, c=12.2724(1) A and β=109.037(6)° as cell parameters. It exhibits an original structure with a new type of iron selenide polyhedra. These data were consistent with the powder X-ray diffraction and TEM analyses. Their electronic structures point towards metallicity and electronic correlations for both selenides. - Graphical abstract: Experimental [010] oriented ED pattern and corresponding HREM image of Ba{sub 4}Fe{sub 3}Se{sub 10}. Image calculated with a focus and thickness to 15nm and 8 nm respectively is inserted. Bright contrasts are correlated to Se rows belonging to FeSe{sub 3}(Se{sub 2}){sup 2−}–FeSe{sub 6}–FeSe{sub 3}(Se{sub 2}){sup 2−} trimers.more » The corresponding structure projection is also shown. - Highlights: • Two new barium iron selenide compounds. • An original structure type Ba4Fe3Se10. • Electronic structure calculations.« less
Published: 2015

30. A vanadium oxy-phosphate Na 4 VO(PO 4 ) 2 as cathode material for Na ion batteries

Author: Antoine Maignan, Noureddine Amdouni, E. Anger, M. Freire, Valerie Pralong, W. Deriouche, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Faculté des Sciences Mathématiques, Physiques et Naturelles de Tunis (FST), Université de Tunis El Manar (UTM), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Lithium vanadium phosphate battery, Sodium, Inorganic chemistry, Ionic bonding, Vanadium, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, Electrochemistry, 01 natural sciences, 7. Clean energy, Na-ion batteries, Phase (matter), General Materials Science, ComputingMilieux_MISCELLANEOUS, Vanadium phosphate, Sodium-ion battery, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, chemistry, Na4VO(PO4)2, 0210 nano-technology, Solid solution
Abstract: International audience; The Na4VO(PO4)2 phase has been synthesized using a solid state route in sealed tubes. This phase crystallizing in the orthorhombic system has a one-dimensional structure built up of corner shared VO6 and PO4 polyhedra. It is an ionic conductor with a conductivity of 10−4S/cm at 500 K and an activation energy of 0.63eV. The electrochemical properties of Na4VO(PO4)2 as a positive electrode in a sodium ion battery have been studied. Results show the possibility of extracting almost one sodium through a two-phase process at 3.4 V leading to the phase Na3.2VO(PO4)2 and to insert as well one sodium at low potential 1.5 V, to form through a solid solution process the reduced phase Na5VO(PO4)2. This study is a proof of the great versatility of vanadium V3+/V4+/V5+ ions in Na-based batteries.
Published: 2017

31. Charge ordering and multiferroicity in Fe3BO5 and Fe2MnBO5 oxyborates

Author: A. Guesdon, Christine Martin, A. Maignan, Sylvie Malo, F. Lainé, Françoise Damay, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Microélectronique et de Physique des Semiconducteurs (LaMIPS), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-NXP Semiconductors [France]-Presto Engineering Europe, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), French-Romanian project ANR-UEFISCDI [8 RO-FR/01.01.2013, PN-II-ID-JRP-2011-2-0056/ANR-12-IS08-0003], COFeIn, École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-NXP Semiconductors [France], Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Normandie Université (NU)-Normandie Université (NU)-NXP Semiconductors [France]-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Magnetism, 02 engineering and technology, Dielectric, Crystal structure, 01 natural sciences, Inorganic Chemistry, Charge ordering, Transition metal, 0103 physical sciences, Materials Chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, Antiferromagnetism, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, 010306 general physics, Multiferroism, Condensed matter physics, Oxide, Oxyborate, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Pyroelectricity, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, Ceramics and Composites, 0210 nano-technology, Superparamagnetism
Abstract: The comparison of Fe 3 BO 5 and Fe 2 MnBO 5 reveals that the 2Fe 2+ : Fe 3+ charge ordering of the former is suppressed in the latter. Spin dynamics probed by ac susceptibility are strongly affected by the substitution, inducing superparamagnetism at low temperature in Fe 2 MnBO 5 . Interestingly, for both oxyborates, glassiness is observed in the dielectric properties at low temperature, but only Fe 3 BO 5 shows a magnetodielectric effect close to its lower magnetic transition. A change in the electrical polarization, measured by pyroelectric current integration, is observed in Fe 3 BO 5 and is even more pronounced in Fe 2 MnBO 5 . Such results suggest that these oxyborates behave like antiferromagnetic relaxor ferroelectrics. These features are proposed to be related to the distribution of the species (Fe 3+ , Fe 2+ and Mn 2+ ) over the four transition metal sites forming the ludwigite structure.
Published: 2017

32. Suppression of superconductivity and resistivity anomaly in Rh17S15 by cobalt substitution

Author: Ramzy Daou, David Berthebaud, Antoine Maignan, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)
Subjects: Materials science, Chalcogenide, Rh17S15, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, chemistry.chemical_compound, symbols.namesake, Pauli exclusion principle, Electrical resistivity and conductivity, Condensed Matter::Superconductivity, 0103 physical sciences, Seebeck effect, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, General Materials Science, 010306 general physics, Critical field, Superconductivity, Condensed matter physics, superconductivity, Doping, Hall effect, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry, symbols, Anomaly (physics), 0210 nano-technology, Cobalt
Abstract: International audience; The chalcogenide superconductor Rh17S15 is known for having an upper critical field of nearly twice the Pauli limit and an unusual temperature dependence of the resistivity. When doped with small amounts of cobalt, superconductivity in Rh17-xCoxS15 (0 < x < 3) is systematically suppressed. We explore the evolution of the electrical transport properties from 2-300 K as a function of x. We identify three temperature regimes which are differently affected by doping. The disappearance of an electron-like contribution to the transport at low temperature is correlated with the suppression of superconductivity.
Published: 2017

33. Revisiting Hollandites Channels Filling by Main-Group Elements Together with Transition Metals in Bi2-yVyV8O16

Author: S. Hébert, Christine Martin, A. Maignan, Arkady V. Krasheninnikov, V. Roddatis, Stuart Turner, Yuri Grin, O. I. Lebedev, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Laboratoire de Microélectronique et de Physique des Semiconducteurs (LaMIPS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-NXP Semiconductors [France]-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Georg-August-University [Göttingen], University of Antwerp (UA), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Aalto University, Academy of Finland [286279], Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST 'MISiS' [K2-2015-033], CSC-IT Center for Science Ltd., Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-NXP Semiconductors [France], Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-NXP Semiconductors [France]-Presto Engineering Europe, Georg-August-University = Georg-August-Universität Göttingen, National University of Science and Technology (MISIS), Max-Planck-Institut für Chemische Physik fester Stoffe (CPfS), and Max-Planck-Gesellschaft
Subjects: Materials science, General Chemical Engineering, Vanadium, chemistry.chemical_element, Mineralogy, 02 engineering and technology, DFT calculations, 01 natural sciences, Quantum mechanics, Ion, Transition metal, Oxidation state, Electrical resistivity and conductivity, Hollandite, Seebeck coefficient, Cations, 0103 physical sciences, Materials Chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, hollandites, [CHIM]Chemical Sciences, Scanning transmission electron microscopy, 010306 general physics, defects, Condensed matter physics, ta114, Physics, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Chemistry, chemistry, TEM, Crystallite, 0210 nano-technology, Transmission electron microscopy
Abstract: International audience; Starting from the nominal BixV8O16 formula, we have performed a stateof-the-art transmission electron microscopy investigation to propose a new Bi2-yVyV8O16 chemical formula for this hollandite structure. This results from the filling of the channels by main-group elements together with vanadium (V5+) species, with a variable content of Bi and V inside the channels. The influence of the Bi content and of this local disorder on the magnetic and transport properties has been investigated in polycrystalline samples of BixV8O16 with nominal x = 1.6 and x = 1.8 compositions. The rather x-independent electrical resistivity (approximate to 5 m Omega cm) and Seebeck coefficient at high T (-35 mu V K-1 at 900 K) are discussed in terms of an unchanged V oxidation state resulting from the filling of the wide channels with Bi and V. It is proposed that this local disorder hinders the charge/orbital setting below 60 K on the V ions of the V8O16 framework. Hollandites exhibit complex electronic and magnetic properties and have potential applications in the fields of batteries, photocatalysis, and nuclear waste storage, and these results show that a careful and detailed investigation of the nature and content of the cations inside the channels is crucial for improving our understanding of the impact of doping and disorder on their properties.
Published: 2017

34. Impact of the iron substitution on the thermoelectric properties of Co 1− x Fe x S 2 ( x ≤ 0.30)

Author: Jean Juraszek, Antoine Maignan, Fabienne Richomme, Sylvie Hébert, Denis Pelloquin, Ismail Fourati, and Ulises Acevedo Salas
Subjects: Materials science, Condensed matter physics, Magnetism, General Mathematics, Substitution (logic), General Engineering, General Physics and Astronomy, 02 engineering and technology, engineering.material, 021001 nanoscience & nanotechnology, 01 natural sciences, 7. Clean energy, Thermal conductivity, Ferromagnetism, 13. Climate action, 0103 physical sciences, Thermoelectric effect, engineering, Pyrite, 010306 general physics, 0210 nano-technology
Abstract: The strong interplay between magnetism and transport can tune the thermoelectric properties in chalcogenides and oxides. In the case of ferromagnetic CoS 2 pyrite, it was previously shown that the power factor is large at room temperature, reaching 1 mW m −1 K −2 and abruptly increases for temperatures below the Curie transition ( T C ), an increase potentially due to a magnonic effect on the Seebeck ( S ) coefficient. The too large thermal conductivity approximately equal to 10.5 W m −1 K −1 at room temperature prevents this pyrite from being a good thermoelectric material. In this work, samples belonging to the Co 1− x Fe x S 2 pyrite family ( x = 0, 0.15 and 0.30) have thus been investigated in order to modify the thermal properties by the introduction of disorder on the Co site. We show here that the thermal conductivity can indeed be reduced by such a substitution, but that this substitution predominantly induces a reduction of the electronic part of the thermal conductivity and not of the lattice part. Interestingly, the magnonic contribution to S below T C disappears as x increases, while at high T , S tends to a very similar value (close to −42 µV K −1 ) for all the samples investigated. This article is part of a discussion meeting issue ‘Energy materials for a low carbon future’.
Published: 2019

35. Multiferroics and Magnetoelectrics: A Comparison between Some Chromites and Cobaltites

Author: Christine Martin, K. R. S. Preethi Meher, A. Maignan, Françoise Damay, and Vincent Caignaert
Subjects: Materials science, Condensed matter physics, General Chemical Engineering, Point reflection, Mineralogy, General Chemistry, Ferroelectricity, Cobaltite, Condensed Matter::Materials Science, Coupling (physics), chemistry.chemical_compound, chemistry, Ferrimagnetism, Materials Chemistry, Antiferromagnetism, Condensed Matter::Strongly Correlated Electrons, Multiferroics, Ground state
Abstract: Oxides containing magnetic 3d transition metals offer a large family of structures with frustrated magnetic networks. Some of those incommensurate antiferromagnetic structures are responsible for the local breaking of inversion symmetry so that these oxides are called spin-induced ferroelectrics. As listed in the introduction of this short review, the number of these multiferroics continues to increase. As for applications, the coupling between these ferroisms is needed; some magnetic oxides, despite a lack of ferroelectric ground state, exhibit large magnetoelectric coupling with a magnetic-field-induced polarization. Thus, they are classified as “magnetoelectrics”. In the present review, we focus on recently studied systems showing ferroelectric-like behaviors or large magnetoelectric coefficients. This will be illustrated by chromites with the comparison between ceramics of CuCrO2 and AgCrS2: they exhibit different antiferromagnetic ground states, centrosymmetric and noncentrosymmetric. For the magneto...
Published: 2013

36. Nanostructures in LuFe2O4+δ

Author: Maryvonne Hervieu, Erik Elkaim, Françoise Damay, Antoine Maignan, Artem M. Abakumov, Christine Martin, G. Van Tendeloo, Maria Poienar, and Jérôme Rouquette
Subjects: Materials science, Condensed matter physics, Neutron diffraction, Stacking, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Synchrotron, law.invention, Charge ordering, Crystallography, law, Transmission electron microscopy, 0103 physical sciences, Ferrite (magnet), General Materials Science, 010306 general physics, 0210 nano-technology, Crystal twinning, Monoclinic crystal system
Abstract: A LuFe 2 O 4+ δ sample, previously characterized by X-ray synchrotron and neutron diffraction, has been studied by electron microscopy techniques, in order to get a precise description of its micro- and nanostructures at room temperature. The X-ray synchrotron data vs . temperature show that the monoclinic distortion is associated with the charge ordering; this distortion results in elongated twinning domains, which enhance the complexity of the microstructural state at room temperature. The structural modulation associated with oxygen excess is observed in large domains inside a non modulated matrix, in contrast with the modulations associated with the charge ordering of the Fe 2+ and Fe 3+ species, which are mostly short-range. The investigation of the nature and density of defects in the sample shows that they are nano-scaled, preserving the regularity of the layer stacking mode, and limited to the formation of one- or two-units large stacking faults, associated with gliding mechanisms. Based on these observations, an original description of the LuFe 2 O 4 ferrite structure, through puckered [LuO 4 ] ∞ sandwiching [Fe 2 ] ∞ layers, is proposed.
Published: 2013

37. From oxides to selenides and sulfides: The richness of the CdI2 type crystallographic structure for thermoelectric properties

Author: Nunna Raghavendra, Emmanuel Guilmeau, Sylvie Hébert, Yohann Bréard, Wataru Kobayashi, Franck Gascoin, Antoine Maignan, and Hervé Muguerra
Subjects: Materials science, Ionic bonding, Mineralogy, Surfaces and Interfaces, Condensed Matter Physics, Thermoelectric materials, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Electrical resistivity and conductivity, Hall effect, Chemical physics, Seebeck coefficient, Thermoelectric effect, Materials Chemistry, Electrical and Electronic Engineering, Single crystal, Solid solution
Abstract: In this paper, we show how the thermoelectric properties can be modified in crystallographic structures based on the CdI2 type layer, by changing the block layers between these CdI2 type layers or by going from oxides to selenides and sulfides. In the case of oxides, the unique properties generated in these structures will be demonstrated in Bi-based misfit compounds. By combining Hall effect, resistivity, and Seebeck coefficients in single crystals of this family, the importance of doping and of spin and orbital degeneracy term on the Seebeck coefficient will be shown. From this single crystal investigation, the power factor at 300 K is found to be unexpectedly constant as a function of doping. To further enhance the power factor and thus ZT, it is necessary to modify either the block layer or to perform anionic substitutions. By going from oxides to selenides and sulfides, the decrease of the ionic character can induce a decrease of electrical resistivity. Compared to oxides, the properties can generally be described in a more classical way using Boltzmann transport theory. For these materials, the critical parameter is then thermal conductivity and this quantity can be decreased as shown here by intercalating Cu between the layers (CuxTiS2), or by making solid solution such as TiS2 − xSex. These two approaches will be described here, leading to ZT close to 0.5 and 0.4, at 800 and 700 K, respectively.
Published: 2012

38. Spin reorientation, magnetization reversal, and negative thermal expansion observed inRFe0.5Cr0.5O3perovskites(R=Lu,Yb,Tm)

Author: Gabriel J. Cuello, Raúl E. Carbonio, Antoine Maignan, Rodolfo Sánchez, Christin Martin, and Fernando Pomiro
Subjects: Physics, Magnetic structure, Magnetic moment, Condensed matter physics, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetic susceptibility, Magnetization, Negative thermal expansion, 0103 physical sciences, Antiferromagnetism, Condensed Matter::Strongly Correlated Electrons, Orthorhombic crystal system, 010306 general physics, 0210 nano-technology, Perovskite (structure)
Abstract: Three members of the perovskite family $R\mathrm{F}{\mathrm{e}}_{0.5}\mathrm{C}{\mathrm{r}}_{0.5}{\mathrm{O}}_{3}$ ($R=\mathrm{Lu},\mathrm{Yb}$, and Tm) have been synthesized and characterized. A systematic study of the crystal and magnetic structures was performed by neutron powder diffraction combined with magnetization measurements. All these compounds crystallize in a Pbnm orthorhombic unit cell and they are already antiferromagnetic at room temperature. The study of the magnetic structure vs temperature showed the occurrence of a progressive spin reorientation from ${\mathrm{\ensuremath{\Gamma}}}_{4}^{\text{TM}}$ to ${\mathrm{\ensuremath{\Gamma}}}_{2}^{\text{TM}}$ for the transition metal sublattice, and in the Tm-based sample, a long-range magnetic order of the $\mathrm{T}{\mathrm{m}}^{3+}$ sublattice was found $({\mathrm{\ensuremath{\Gamma}}}_{8}^{R})$. These results are in excellent agreement with the magnetic susceptibility measurements. No spin reorientation is observed in the Lu-based sample for which a magnetization reversal at a compensation temperature ${T}_{\mathrm{comp}}=225\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ was detected. A clear magnetostrictive effect was observed in the samples with $R=\mathrm{Yb}$ and Tm associated with a negative thermal expansion and was assigned to a magnetoelastic effect produced by repulsion between the magnetic moments of neighboring transition metal ions.
Published: 2016

39. COMPOSITION-INDUCED SUPERCONDUCTIVITY (UP TO 55-K) IN THE SYSTEM (PB0.75CU0.25)SR2(CA1-XYX)CU2O7-DELTA

Author: I. Gameson, Peter P. Edwards, B. Raveau, A. Maignan, T. Rouillon, Shu Fen Hu, Ru-Shi Liu, and Daniel Groult
Subjects: Superconductivity, X-ray spectroscopy, Chemistry, Transition temperature, Inorganic chemistry, Analytical chemistry, Crystal structure, Atmospheric temperature range, Condensed Matter Physics, Magnetic susceptibility, Electronic, Optical and Magnetic Materials, Inorganic Chemistry, Electrical resistivity and conductivity, X-ray crystallography, Materials Chemistry, Ceramics and Composites, Physical and Theoretical Chemistry
Abstract: The authors demonstrate a compositionally induced superconductor-to-semiconductor transition in the system (Pb{sub 0.75}Cu{sub 0.25})Sr{sub 2}(Ca{sub 1{minus}x}Y{sub x})Cu{sub 2}O{sub 7-{delta}}. Superconducting behavior is observed over the composition range 0.1 {le} x {le} 0.6. Samples with 0.1 {le} x {le} 0.3 are multiphasic, but the superconducting transition temperature is a maximum (55 K) over this range of compositions. The sample having x = 0.5 gives rise to an acceptable phase purity, a superconducting transition temperature of 45 K, and the maximum superconducting (Meissner) volume fraction (20.2%). A superconductor-to-semiconductor transition occurs at x = 0.7.
Published: 2016

40. ChemInform Abstract: Searching for New Thermoelectric Materials: Some Examples Among Oxides, Sulfides and Selenides

Author: O. I. Lebedev, S. Hébert, Ramzy Daou, Franck Gascoin, Emmanuel Guilmeau, Denis Pelloquin, A. Maignan, Yohann Bréard, and David Berthebaud
Subjects: Lattice (module), Chalcogen, Thermal conductivity, Condensed matter physics, Chemistry, Seebeck coefficient, Degenerate energy levels, Thermoelectric effect, General Medicine, Thermoelectric materials
Abstract: Different families of thermoelectric materials have been investigated since the discovery of thermoelectric effects in the mid-19th century, materials mostly belonging to the family of degenerate semi-conductors. In the last 20 years, new thermoelectric materials have been investigated following different theoretical proposals, showing that nanostructuration, electronic correlations and complex crystallographic structures (low dimensional structures, large number of atoms per lattice, presence of 'rattlers'…) could enhance the thermoelectric properties by enhancing the Seebeck coefficient and/or reducing the thermal conductivity. In this review, the different strategies used to optimize the thermoelectric properties of oxides and chalcogenides will be presented, starting with a review on thermoelectric oxides. The thermoelectric properties of sulfides and selenides will then be discussed, focusing on layered materials and low dimensional structures (TiS2 and pseudo-hollandites). Some sulfides with promising ZT values will also be presented (tetrahedrites and chalcopyrites).
Published: 2016

41. Hydrothermal synthesis for new multifunctional materials: A few examples of phosphates and phosphonate-based hybrid materials

Author: Jean-Michel Rueff, Antoine Maignan, Anne Guesdon, Paul-Alain Jaffrès, Maria Poienar, Christine Martin, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), National Institute for Research and Development in Electrochemistry and Condensed Matter (NIRDElCM), Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Université de Brest (UBO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Nanostructure, Nanotechnology, Hybrids, 02 engineering and technology, Advanced materials, 010402 general chemistry, 01 natural sciences, Hydrothermal circulation, Phosphates, Inorganic Chemistry, chemistry.chemical_compound, Materials Chemistry, Hydrothermal synthesis, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, Oxides, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Phosphonate, Hydrothermal, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, chemistry, Iron based, Ceramics and Composites, Phosphonates, 0210 nano-technology, Hybrid material
Abstract: International audience; Novel physical or chemical properties are expected in a great variety of materials, in connection with the dimensionality of their structures and/or with their nanostructures, hierarchical superstructures etc. In the search of new advanced materials, the hydrothermal technique plays a crucial role, mimicking the nature able to produce fractal, hyperbranched, urchin-like or snow flake structures. In this short review including new results, this will be illustrated by examples selected in two types of materials, phosphates and phosphonates, prepared by this method. The importance of the synthesis parameters will be highlighted for a magnetic iron based phosphates and for hybrids containing phosphonates organic building units crystallizing in different structural types.
Published: 2016

42. Localised Ag+ vibrations at the origin of ultralow thermal conductivity in layered thermoelectric AgCrSe2

Author: Christine Martin, Ramzy Daou, S. Petit, Franck Gascoin, Antoine Maignan, Françoise Damay, Marcel Braendlein, François Fauth, S. Rols, Erik Elkaim, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Groupe 3 axes (G3A), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Laue-Langevin (ILL), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), ALBA Synchrotron light source [Barcelone], Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Institut Rayonnement Matière de Saclay (IRAMIS), ILL, École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), and European Synchrotron Radiation Facility (ESRF)
Subjects: Multidisciplinary, Materials science, Condensed matter physics, Phonon, Anharmonicity, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, Conductivity, 021001 nanoscience & nanotechnology, Thermoelectric materials, 01 natural sciences, Inelastic neutron scattering, Article, Magnetic field, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Thermal conductivity, 0103 physical sciences, Thermoelectric effect, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, 010306 general physics, 0210 nano-technology
Abstract: In materials science, the substructure approach consists in imagining complex materials in which a particular property is associated with a distinct structural feature, so as to combine different chosen physical characteristics, which otherwise have little chance to coexist. Applied to thermoelectric materials, it has been used to achieve simultaneously phonon-glass and electron-crystal properties. Mostly studied for its superionic conductivity, AgCrSe2 is a naturally layered compound, which achieves very low thermal conductivity, ~0.4 W.K−1.m−1 at RT (room temperature) and is considered a promising thermoelectric. The Cr atoms of the [CrSe2]∞ layer bear a spin S = 3/2, which orders below TN = 55 K. Here we report low temperature inelastic neutron scattering experiments on AgCrSe2, alongside the magnetic field evolution of its thermal and electrical transport. We observe a very low frequency mode at 3 meV, ascribed to large anharmonic displacements of the Ag+ ions in the [Ag]∞ layer and 2D magnetic fluctuations up to 3 TN in the chromium layer. The low thermal conductivity of AgCrSe2 is attributed to acoustic phonon scattering by a regular lattice of Ag+ oscillating in quasi-2D potential wells. These findings highlight a new way to achieve localised phonon modes in a perfectly crystalline solid.
Published: 2016
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43. Magnetization reversal in mixed ferrite-chromite perovskites with non magnetic cation on the A-site

Author: Sergio A. Cannas, Raúl E. Carbonio, Christine Martin, Orlando V. Billoni, Fernando Pomiro, Antoine Maignan, Universidad Nacional de Córdoba [Argentina], Instituto de Fisica Enrique Gaviola (IFEG), Instituto de Investigaciones en Físico Química [Córdoba] (INFIQC), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Facultad de Ciencias Químicas [Córdoba], Universidad Nacional de Córdoba [Argentina]-Universidad Nacional de Córdoba [Argentina], Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, PEROVSKITE, REVERSAL, Ciencias Físicas, Monte Carlo method, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Classical spin models, Ion, DM interactions, Magnetization reversal, 0103 physical sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, General Materials Science, Perovskites, 010306 general physics, Condensed Matter - Materials Science, Antisymmetric exchange, Condensed matter physics, Spins, MONTE, Materials Science (cond-mat.mtrl-sci), MAGNETIZATION, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Astronomía, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, CARLO, Mean field theory, Ferromagnetism, Ferrite (magnet), Condensed Matter::Strongly Correlated Electrons, Chromite, 0210 nano-technology, CIENCIAS NATURALES Y EXACTAS
Abstract: In this work, we have performed Monte Carlo simulations in a classical model for RFe$_{1-x}$Cr$_x$O$_3$ with R=Y and Lu, comparing the numerical simulations with experiments and mean field calculations. In the analyzed compounds, the antisymmetric exchange or Dzyaloshinskii-Moriya (DM) interaction induced a weak ferromagnetism due to a canting of the antiferromagnetically ordered spins. This model is able to reproduce the magnetization reversal (MR) observed experimentally in a field cooling process for intermediate $x$ values and the dependence with $x$ of the critical temperatures. We also analyzed the conditions for the existence of MR in terms of the strength of DM interactions between Fe$^{3+}$ and Cr$^{3+}$ ions with the x values variations., 8 pages, 7 figures
Published: 2016

44. The BiCu1−xOS oxysulfide Copper deficiency and electronic properties

Author: Antoine Maignan, Philippe Barboux, Emmanuel Guilmeau, Oleg I. Lebedev, J. Gamon, David Berthebaud, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche de Chimie Paris (IRCP), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, chemistry.chemical_element, Mineralogy, 02 engineering and technology, 010402 general chemistry, Epitaxy, 01 natural sciences, Bismuth, Inorganic Chemistry, Electrical resistivity and conductivity, Seebeck coefficient, Materials Chemistry, medicine, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Oxysulfide, Physical and Theoretical Chemistry, Electronic properties, Superconductivity, Ternary numeral system, Electrical resistivity, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, medicine.disease, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, chemistry, Thermopower, Ceramics and Composites, HAADF-STEM, 0210 nano-technology, Copper deficiency
Abstract: International audience; An oxysulfide series of nominal compositions BiCu1−xOS with xandlt;0.20 has been prepared and its structural properties characterized by combining powder X-ray diffraction and transmission electron microscopy techniques. It is found that this oxysulfide, crystallizing in the P4/nmm space group, tends to adopt a constant amount of copper vacancy corresponding to x=0.05 in the BiCu1−xOS formula. The presence of Cu vacancies is confirmed by HAADF-STEM analysis showing, in the Cu atomic columns, alternating peaks of different intensities in some very localized regions. For larger Cu deficiencies (xandgt;0.05 in the nominal composition), other types of structural nanodefects are evidenced such as bismuth oxysulfides of the “BiOS” ternary system which might explain the report of superconductivity for the BiCu1−xOS oxysulfide. Local epitaxial growth of the BiCuOS oxysulfide on top of CuO is also observed. In marked contrast to the BiCu1−xOSe oxyselenide, these results give an explanation to the limited impact of Cu deficiency on the Seebeck coefficient in BiCu1−xOS compounds. © 2016 Elsevier Inc.
Published: 2016

45. Robustness of Antiferromagnetism and Pyroelectricity in AgCr 1-x Rh x S 2

Author: Natalia E. Mordvinova, E. Pachoud, Christine Martin, Françoise Damay, Antoine Maignan, O. I. Lebedev, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay
Subjects: Materials science, Sulfide, Magnetoelastic effects, General Chemical Engineering, chemistry.chemical_element, 02 engineering and technology, Dielectric, 01 natural sciences, Quantum mechanics, Rhodium, Antiferromagnetic transition temperature, Chromium, Antiferromagnetism, Random characters, Chemical structure, Polarization, Cations, 0103 physical sciences, Magnetic properties, Materials Chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Electrical polarization, 010306 general physics, Polarization (electrochemistry), chemistry.chemical_classification, Crystallography, Dielectric permittivities, Condensed matter physics, Peak temperatures, Transition temperature, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Pyroelectricity, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Structural studies, chemistry, Dielectric properties, Permittivity, 0210 nano-technology, Magnetic and dielectric properties
Abstract: International audience; The effect of the rhodium for chromium substitution in AgCr 1-x Rh x S 2 on the magnetic and dielectric properties has been studied in the 0.0 ≤ x ≤ 0.5 range. It is found that the antiferromagnetic transition temperature T N decreases as x increases by about -0.9 K per %Rh up to x = 0.30. Consequently, the peak temperature in the real part of the dielectric permittivity, associated with T N , is observed to decrease by the same amount. Moreover, the electrical polarization magnitude induced below T N in this pyroelectric sulfide tends to decrease with x increasing. This is consistent with the structural study showing the random character of the substitution, which creates both magnetic dilution and more symmetric local structure. These two factors are expected to hinder the magnetoelastic effect supposed to be responsible for the electrical polarization change in AgCrS 2 at T N . © 2016 American Chemical Society.
Published: 2016

46. Co-substitution at the Mn-site in YMnO3: Structural stability and physical properties

Author: Antoine Maignan and S. Malo
Subjects: Materials science, Mechanical Engineering, Oxide, Space group, Condensed Matter Physics, chemistry.chemical_compound, Crystallography, chemistry, Mechanics of Materials, Oxidation state, X-ray crystallography, Antiferromagnetism, General Materials Science, Multiferroics, Solubility, Solid solution
Abstract: The YMnO 3 oxide, crystallizing in the P6 3 cm space group is one of the most studied multiferroic material. While these properties can be modified by substitutions at the Mn-site, the peculiar fivefold coordination appears to limit the M solubility range in YMn 1− x M x O 3 . This motivated the preparation by solid state reaction of several series of co-substituted YMn 1− x (M′,M″) x O 3 , which were studied using both powder X-ray diffraction and transmission electron microscopy. The cation pairs have been chosen for their ability to adopt a fivefold coordination similar to that of Mn 3+ in YMnO 3 , to keep a constant average trivalent oxidation state and to maintain an average cationic radius similar to that of Mn 3+ . For YMn 1− x (Cu 1/2 Ti 1/2 ) x O 3 , a complete solid solution is observed without cation ordering. For all other studied cation pairs, the solubility range is always reaching a minimum value of 25% for the Zn containing pairs (Zn 2/3 V 1/3 and Zn 3/4 Mo 1/4 ), a maximum of 50% being reached for the Cu containing pairs (Cu 2/3 V 1/3 , Cu 2/3 Nb 1/3 and Cu 3/4 W 1/4 ). Interestingly, the non-centrosymmetric P6 3 cm space group is retained within the solubility range without generating cation ordering phenomena. These co-substitutions at the Mn 3+ are found to induce a decrease of the antiferromagnetic ordering temperature, the T N variations being similar to the temperature decrease of the dielectric anomaly. Thus, these oxides are interesting candidates for the study of the multiferroic behavior of YMnO 3 derivatives.
Published: 2012

47. Impact of short-range order on transport properties of the two-dimensional metal PdCrO$_2$

Author: Sylvie Hébert, Ramzy Daou, Antoine Maignan, Raymond Frésard, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Frustrated magnetism, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Nernst effect, Superconductivity (cond-mat.supr-con), symbols.namesake, Antiferromagnetism, Single crystal materials, Hall effect, Condensed Matter::Superconductivity, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 0103 physical sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Nernst equation, Cuprate, Spin density waves, 010306 general physics, Physics, Superconductivity, Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Superconductivity, 2-dimensional systems, Fermi surface, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Phase transitions, symbols, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, Pseudogap
Abstract: International audience; We study the Hall and Nernst effects across the antiferromagnetic transition that reconstructs the quasi-two-dimensional Fermi surface of the metallic local moment antiferromagnet PdCrO2. We show that nonmonotonic temperature dependence in the Hall effect and a sign change in the Nernst effect above the ordering temperature cannot be understood within a simple single-band transport model. The inclusion of coherent scattering by critical antiferromagnetic fluctuations can qualitatively account for these features in the transport coefficients. We discuss the implications of this for the pseudogap phase of the cuprate superconductors, which have a similar Fermi surface and where the same transport signatures are observed. © 2015 American Physical Society.
Published: 2015

48. The ability of RP-type cobaltites to accommodate carbonate groups: A new layered oxide Sr4Co2(CO3)O5.86

Author: Denis Pelloquin, Antoine Maignan, Yohann Bréard, A. Demont, Yuzuru Miyazaki, Sylvie Hébert, and J. Höwing
Subjects: Materials science, Neutron diffraction, Oxide, chemistry.chemical_element, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Cobaltite, Inorganic Chemistry, chemistry.chemical_compound, Magnetization, Crystallography, chemistry, Phase (matter), Materials Chemistry, Ceramics and Composites, Antiferromagnetism, Carbonate, Physical and Theoretical Chemistry, Cobalt
Abstract: The possibility to introduce carbonate groups inside a pure cobalt based Ruddlesden Popper type matrix is demonstrated. This paper reports the synthesis as a single phase of a new layered oxycarbonate Sr4Co2(CO3)O5.86 and its structural characterizations at room temperature combining TEM observations and powder neutron diffraction data. Close structural relationships are observed with the homologous Sr4Fe3−x(CO3)xO10−4x series and deal with the presence of two specific carbonate configurations, namely coat hanger and flag. Magnetization measurements reveal a complex antiferromagnetic behavior below 50 K with three others transitions, at 160, 210 and 250 K. Such behavior can be ascribed to the latent reactivity in air of this largely oxygen deficient phase.
Published: 2011

49. Pinning efficiency of splayed columnar defects in Bi-2212 single crystal: Evidence of a cage pinning effect

Author: Ch. Simon, Antoine Maignan, D. Plessis, V.A. Shaidiuk, A. Wahl, L. Ammor, S. de Brion, and Antoine Ruyter
Subjects: Superconductivity, Materials science, Condensed matter physics, Persistent current, General Chemistry, Condensed Matter Physics, Crystallographic defect, Magnetization, Hysteresis, Electrical resistivity and conductivity, Condensed Matter::Superconductivity, General Materials Science, Anisotropy, Single crystal
Abstract: A three-directional configuration of columnar defects has been induced in a Bi2Sr2CaCu2O8 single crystal by irradiation with heavy ions of high energy. Persistent current densities have been extracted, using the Bean model, from hysteresis loops recorded in the orientation H||c. We have shown that improvements in pinning properties are larger in this three-directional splayed configuration than in the one obtained with columnar defects parallel to the c-axis. This effect exists only for H larger than HΦ, where HΦ is the matching field, and disappears as temperature is increased and vortices become less stiff. This is the first time that such a beneficial effect is reported for a compound of such a high electronic anisotropy.
Published: 2011

50. Substitution Effect on the Interplane Coupling in Crednerite: the Cu1.04Mn0.96O2 Case

Author: C. Vecchini, Aziz Daoud-Aladine, Alexandros Lappas, Maria Poienar, C. Martin, Antoine Maignan, Gilles André, Françoise Damay, Laurent Chapon, Maryvonne Hervieu, and Irene Margiolaki
Subjects: Imagination, Materials science, Condensed matter physics, General Chemical Engineering, media_common.quotation_subject, 02 engineering and technology, General Chemistry, Crystal structure, 021001 nanoscience & nanotechnology, 01 natural sciences, Inductive coupling, Octahedron, Ferromagnetism, Lattice (order), 0103 physical sciences, Materials Chemistry, Antiferromagnetism, Substitution effect, 010306 general physics, 0210 nano-technology, media_common
Abstract: The 4%Cu for Mn substitution in CuMnO2 decreases slightly the lattice parameters, reduces the Jahn−Teller distortion of the MnO6 octahedra, but does not change the temperature dependence of the structure, showing a C2/m to P1 structural transition (in the vicinity of the magnetic transition temperature). In contrast, the antiferromagnetic structure is strongly modified by the substitution, as a propagation vector k = (0 1/2 0) is evidenced for Cu1.04Mn0.96O2 compared to k = (0 1/2 1/2) for CuMnO2. Consequently, the interplane magnetic coupling (along the c axis) changes from antiferromagnetic in CuMnO2 to ferromagnetic in Cu1.04Mn0.96O2 without change in the antiferromagnetic arrangement of the ferromagnetic chains in the (a,b) plane. The nanostructural study points toward the existence of numerous defects at the nanoscale which justify the modeling of strains used in the refinement of the crystalline structure.
Published: 2010

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