123 results on '"Joke Hadermann"'
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2. Structures and Magnetic Ordering in Layered Cr Oxide Arsenides Sr2CrO2Cr2OAs2 and Sr2CrO3CrAs
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Bradley C. Sheath, Xiaoyu Xu, Pascal Manuel, Joke Hadermann, Maria Batuk, John O’Sullivan, Ruy S. Bonilla, and Simon J. Clarke
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Inorganic Chemistry ,Physical and Theoretical Chemistry - Abstract
Two novel chromium oxide arsenide materials have been synthesized, Sr2CrO2Cr2OAs2 (i.e., Sr2Cr3As2O3) and Sr2CrO3CrAs (i.e., Sr2Cr2AsO3), both of which contain chromium ions in two distinct layers. Sr2CrO2Cr2OAs2 was targeted following electron microscopy measurements on a related phase. It crystallizes in the space group P4/mmm and accommodates distorted CrO4As2 octahedra containing Cr2+ and distorted CrO2As4 octahedra containing Cr3+. In contrast, Sr2CrO3CrAs incorporates Cr3+ in CrO5 square-pyramidal coordination in [Sr2CrO3]+ layers and Cr2+ ions in CrAs4 tetrahedra in [CrAs]− layers and crystallizes in the space group P4/nmm. Powder neutron diffraction data reveal antiferromagnetic ordering in both compounds. In Sr2CrO3CrAs the Cr2+ moments in the [CrAs]− layers exhibit long-range ordering, while the Cr3+ moments in the [Sr2CrO3]+ layers only exhibit short-range ordering. However, in Sr2CrO2Cr2OAs2, both the Cr2+ moments in the CrO4As2 environments and the Cr3+ moments in the CrO2As4 polyhedra are long-range-ordered below 530(10) K. Above this temperature, only the Cr3+ moments are ordered with a Néel temperature slightly in excess of 600 K. A subtle structural change is evident in Sr2CrO2Cr2OAs2 below the magnetic ordering transitions.
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- 2022
3. The crystal and defect structures of polar KBiNb2O7
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Subhadip Mallick, Weiguo Zhang, Maria Batuk, Alexandra S. Gibbs, Joke Hadermann, P. Shiv Halasyamani, Michael A. Hayward, University of St Andrews. School of Chemistry, and University of St Andrews. Centre for Designer Quantum Materials
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Inorganic Chemistry ,NDAS ,QD ,QD Chemistry - Abstract
Funding: Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford/Warwick Solid State Chemistry BAG to probe composition-structure– property relationships in solids” (CY25166). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC (RB 2000148). SM thanks Somerville College for an Oxford Ryniker Lloyd scholarship. ‘PSH and WZ thank the National Science Foundation (DMR-2002319) and Welch Foundation (Grant E-1457) for support. KBiNb2O7 was prepared from RbBiNb2O7 by a sequence of cation exchange reactions which first convert RbBiNb2O7 to LiBiNb2O7, before KBiNb2O7 is formed by a further K-for-Li cation exchange. A combination of neutron, synchrotron X-ray and electron diffraction data reveal that KBiNb2O7 adopts a polar, layered, perovskite structure (space group A11m) in which the BiNb2O7 layers are stacked in a (0, ½, z) arrangement, with the K+ cations located in half of the available 10-coordinate interlayer cation sites. The inversion symmetry of the phase is broken by a large displacement of the Bi3+ cations parallel to the y-axis. HAADF-STEM images reveal that KBiNb2O7 exhibits frequent stacking faults which convert the (0, ½, z) layer stacking to (½, 0, z) stacking and vice versa, essentially switching the x- and y-axes of the material. By fitting the complex diffraction peak shape of the SXRD data collected from KBiNb2O7 it is estimated that each layer has approximately a 9% chance of being defective-a high level which is attributed to the lack of cooperative NbO6 tilting in the material, which limits the lattice strain associated with each fault. Publisher PDF
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- 2022
4. Microstructural Activation of a Topochemical Reduction Reaction
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Mylène Hendrickx, Midori Amano Patino, Zhilin Liang, Joke Hadermann, and Michael A. Hayward
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Cultural Studies ,History ,Phase transition ,QD241-441 ,Materials science ,Literature and Literary Theory ,Phase (matter) ,Organic chemistry ,Physical chemistry ,Redox ,Inorganic chemistry ,QD146-197 - Abstract
The progress of the topochemical reduction reaction that converts LaSrNiRuO6 into LaSrNiRuO4 depends on the synthesis conditions used to prepare the oxidized phase. Samples of LaSrNiRuO6 that have been quenched from high temperature can be readily and rapidly converted into LaSrNiRuO4. In contrast, samples that have been slow-cooled cannot be completely reduced. This reactivity difference is attributed to the differing microstructures of the quenched and slow-cooled samples, with the former having much smaller average crystalline domain sizes and larger lattice strains than the latter. A mechanism to explain this effect is presented, in which the greater “plasticity” of small crystalline domains helps lower the activation energy of the reduction reaction. In addition, we propose that the enhanced lattice strain in quenched samples also acts to destabilize the host phase, further enhancing reactivity. These observations suggest that the microstructure of a material can be used to “activate” topochemical reactions in the solid state, expanding the scope of phases that can be prepared by this type of reaction.
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- 2021
5. Ambient and High Pressure CuNiSb2: Metal-Ordered and Metal-Disordered NiAs-Type Derivative Pnictides
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Chongin Pak, David Walker, Thomas J. Emge, Martha Greenblatt, Gabriel Kotliar, Xiaoyan Tan, Corey E. Frank, Saul H. Lapidus, Chang-Jong Kang, Callista M. Skaggs, Christopher J. Perez, Joke Hadermann, and Susan M. Kauzlarich
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education.field_of_study ,Rietveld refinement ,Chemistry ,Population ,Thermoelectric materials ,Electron localization function ,Inorganic Chemistry ,Crystal ,Paramagnetism ,Crystallography ,Seebeck coefficient ,Physical and Theoretical Chemistry ,education ,Single crystal - Abstract
The mineral Zlatogorite, CuNiSb2, was synthesized in the laboratory for the first time by annealing elements at ambient pressure (CuNiSb2-AP). Rietveld refinement of synchrotron powder X-ray diffraction data indicates that CuNiSb2-AP crystallizes in the NiAs-derived structure (P3m1, #164) with Cu and Ni ordering. The structure consists of alternate NiSb6 and CuSb6 octahedral layers via face-sharing. The formation of such structure instead of metal disordered NiAs-type structure (P63/mmc, #194) is validated by the lower energy of the ordered phase by first-principle calculations. Interatomic crystal orbital Hamilton population, electron localization function, and charge density analysis reveal strong Ni-Sb, Cu-Sb, and Cu-Ni bonding and long weak Sb-Sb interactions in CuNiSb2-AP. The magnetic measurement indicates that CuNiSb2-AP is Pauli paramagnetic. First-principle calculations and experimental electrical resistivity measurements reveal that CuNiSb2-AP is a metal. The low Seebeck coefficient and large thermal conductivity suggest that CuNiSb2 is not a potential thermoelectric material. Single crystals were grown by chemical vapor transport. The high pressure sample (CuNiSb2-8 GPa) was prepared by pressing CuNiSb2-AP at 700 °C and 8 GPa. However, the structures of single crystal and CuNiSb2-8 GPa are best fit with a disordered metal structure in the P3m1 space group, corroborated by transmission electron microscopy.
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- 2020
6. Chemistry, local molybdenum clustering, and electrochemistry in the <tex>Li_{2+x}Mo_{1-x}O_{3}$</tex> solid solutions
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Aleksandra A. Savina, Viktoriia V. Saiutina, Anatolii V. Morozov, Anton O. Boev, Dmitry A. Aksyonov, Catherine Dejoie, Maria Batuk, Sara Bals, Joke Hadermann, and Artem M. Abakumov
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Inorganic Chemistry ,Chemistry ,Physical and Theoretical Chemistry - Abstract
A broad range of cationic nonstoichiometry has been demonstratedfor the Li-rich layered rock-salt-type oxide Li2MoO3, which has generally been considered as a phase with a well-defined chemical composition. Li2+xMo1-xO3(-0.037
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- 2022
7. The influence of the 6s2 configuration of Bi3+ on the structures of A′BiNb2O7 (A′ = Rb, Na, Li) layered perovskite oxides
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Michael A. Hayward, Guru Khalsa, Subhadip Mallick, Maria Batuk, Joke Hadermann, Alexandra S. Gibbs, Jeffrey Z Kaaret, Weiguo Zhang, P. Shiv Halasyamani, and Nicole A. Benedek
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Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Materials science ,chemistry ,Acentric factor ,Oxide ,Space group ,Polar ,Electron configuration ,Crystal structure ,Ferroelectricity ,Perovskite (structure) - Abstract
Solid state compounds which exhibit non-centrosymmetric crystal structures are of great interest due to the physical properties they can exhibit. The ‘hybrid improper’ mechanism – in which two non-polar distortion modes couple to, and stabilize, a further polar distortion mode, yielding an acentric crystal structure – offers opportunities to prepare a range of novel non-centrosymmetric solids, but examples of compounds exhibiting acentric crystal structures stabilized by this mechanism are still relatively rare. Here we describe a series of bismuth-containing layered perovskite oxide phases, RbBiNb2O7, LiBiNb2O7and NaBiNb2O7, which have structural frameworks compatible with hybrid-improper ferroelectricity, but also contain Bi3+cations which are often observed to stabilize acentric crystal structures due to their 6s2electronic configurations. Neutron powder diffraction analysis reveals that RbBiNb2O7and LiBiNb2O7adopt polar crystal structures (space groupsI2cmandB2cmrespectively), compatible with stabilization by a trilinear coupling of non-polar and polar modes. The Bi3+cations present are observed to enhance the magnitude of the polar distortions of these phases, but are not the primary driver for the acentric structure, as evidenced by the observation that replacing the Bi3+cations with Nd3+cations does not change the structural symmetry of the compounds. In contrast the non-centrosymmetric, but non-polar structure of NaBiNb2O7(space groupP212121) differs significantly from the centrosymmetric structure of NaNdNb2O7, which is attributed to a second-order Jahn-Teller distortion associated with the presence of the Bi3+cations.
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- 2021
8. Quantitative analysis of diffuse electron scattering in the lithium-ion battery cathode material Li1.2Ni0.13Mn0.54Co0.13O2
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Romy Poppe, Daphne Vandemeulebroucke, Reinhard B. Neder, and Joke Hadermann
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Inorganic Chemistry ,Chemistry ,Structural Biology ,Physics ,General Materials Science ,General Chemistry ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Abstract
In contrast to perfectly periodic crystals, materials with short-range order produce diffraction patterns that contain both Bragg reflections and diffuse scattering. To understand the influence of short-range order on material properties, current research focuses increasingly on the analysis of diffuse scattering. This article verifies the possibility to refine the short-range order parameters in submicrometre-sized crystals from diffuse scattering in single-crystal electron diffraction data. The approach was demonstrated on Li1.2Ni0.13Mn0.54Co0.13O2, which is a state-of-the-art cathode material for lithium-ion batteries. The intensity distribution of the 1D diffuse scattering in the electron diffraction patterns of Li1.2Ni0.13Mn0.54Co0.13O2 depends on the number of stacking faults and twins in the crystal. A model of the disorder in Li1.2Ni0.13Mn0.54Co0.13O2 was developed and both the stacking fault probability and the percentage of the different twins in the crystal were refined using an evolutionary algorithm in DISCUS. The approach was applied on reciprocal space sections reconstructed from 3D electron diffraction data since they exhibit less dynamical effects compared with in-zone electron diffraction patterns. A good agreement was achieved between the calculated and the experimental intensity distribution of the diffuse scattering. The short-range order parameters in submicrometre-sized crystals can thus successfully be refined from the diffuse scattering in single-crystal electron diffraction data using an evolutionary algorithm in DISCUS.
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- 2022
9. Exsolution of SrO during the Topochemical Conversion of LaSr3CoRuO8 to the Oxyhydride LaSr3CoRuO4H4
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Lun Jin, Michael A. Hayward, Maria Batuk, Stephen J. Blundell, Franziska K. K. Kirschner, Franz Lang, and Joke Hadermann
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Ion exchange ,010405 organic chemistry ,Chemistry ,Oxide ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Phase (matter) ,Physical chemistry ,Neutron ,Physical and Theoretical Chemistry - Abstract
Reaction of the n = 1 Ruddlesden-Popper oxide LaSr3CoRuO8 with CaH2 yields the oxyhydride phase LaSr3CoRuO4H4 via a topochemical anion exchange. Close inspection of the X-ray and neutron powder diffraction data in combination with HAADF-STEM images reveals that the nanoparticles of SrO are exsolved from the system during the reaction, with the change in cation stoichiometry accommodated by the inclusion of n > 1 (Co/Ru)(n)On+1H2n "perovskite" layers into the Ruddlesden-Popper stacking sequence. This novel pseudotopochemical process offers a new route for the formation of n > 1 Ruddlesden-Popper structured materials. Magnetization data are consistent with a LaSr3Co+Ru2+O4H4 (Co+, d(8), S = 1; Ru2+, d(6), S = 0) oxidation/spin state combination. Neutron diffraction and mu+SR data show no evidence for long-range magnetic order down to 2 K, suggesting the diamagnetic Ru2+ centers impede the Co-Co magnetic-exchange interactions.
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- 2019
10. Tuning the Crystal Structure of A 2 CoPO 4 F (A = Li, Na) Fluoride‐Phosphates: A New Layered Polymorph of LiNaCoPO 4 F
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Artem M. Abakumov, Keith J. Stevenson, Evgeny V. Antipov, Aleksandr Sh. Samarin, Stanislav S. Fedotov, Dmitry A. Aksyonov, Joke Hadermann, Olesia M. Karakulina, and Nellie R. Khasanova
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Inorganic Chemistry ,Chemistry ,Electrode material ,chemistry.chemical_compound ,Inorganic chemistry ,Crystal structure ,Fluoride - Abstract
Co-containing fluoride-phosphates are of interest in sense of delivering high electrode potentials and attractive specific energy values as positive electrode materials for rechargeable batteries. In this paper we report on a new Co-based fluoride-phosphate, LiNaCoPO4F, with a layered structure (2D), which was Rietveld-refined based on X-ray powder diffraction data [P2(1)/c, a = 6.83881(4) angstrom, b = 11.23323(5) angstrom, c = 5.07654(2) angstrom, beta = 90.3517(5) degrees, V = 389.982(3) angstrom(3)] and validated by electron diffraction and high-resolution scanning transmission electron microscopy. The differential scanning calorimetry measurements revealed that 2D-LiNaCoPO4F forms in a narrow temperature range of 520-530 degrees C and irreversibly converts to the known 3D-LiNaCoPO4F modification (Pnma) above 530 degrees C. The non-carbon-coated 2D-LiNaCoPO4F shows reversible electrochemical activity in Li-ion cell in the potential range of 3.0-4.9 V vs. Li/Li+ with an average potential of approximate to 4.5 V and in Na-ion cell in the range of 3.0-4.5 V vs. Na/Na+ exhibiting a plateau profile centered around 4.2 V, in agreement with the calculated potentials by density functional theory. The energy barriers for both Li+ and Na+ migration in 2D-LiNaCoPO4F amount to 0.15 eV along the [001] direction rendering 2D-LiNaCoPO4F as a viable electrode material for high-power Li- and Na-ion rechargeable batteries. The discovery and stabilization of the 2D-LiNaCoPO4F polymorph indicates that temperature influence on the synthesis of A(2)MPO(4)F fluoride-phosphates needs more careful examination with perspective to unveil new structures.
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- 2019
11. Synthesis and Characterization of Double Solid Solution (Zr,Ti)2(Al,Sn)C MAX Phase Ceramics
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Konstantina Lambrinou, Dominique Thiaudière, Louis Hennet, Joke Hadermann, Bensu Tunca, Daniel R. Neuville, Jozef Vleugels, Thomas Lapauw, Rémi Delville, Thierry Ouisse, Physics, University of Antwerp (UA), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire des matériaux et du génie physique (LMGP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire des matériaux et du génie physique (LMGP), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Electron Microscopy for Materials Research, University of Huddersfield, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), and Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)
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XRD ,Analytical chemistry ,Crystal structure ,010402 general chemistry ,Hot pressing ,01 natural sciences ,Thermal expansion ,Inorganic Chemistry ,MAX Phases ,Phase (matter) ,Chemistry, Inorganic & Nuclear ,CRYSTAL-STRUCTURE ,Physical and Theoretical Chemistry ,POWDER ,ComputingMilieux_MISCELLANEOUS ,TI2SNC ,Science & Technology ,010405 organic chemistry ,Chemistry ,Rietveld refinement ,Lattice Distortions ,MECHANICAL-PROPERTIES ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Microstructure ,CTE ,0104 chemical sciences ,Double Solid Solutions ,TI3ALC2 ,OXIDATION RESISTANCE ,Physical Sciences ,MAX phases ,THERMAL-EXPANSION ,TI ,M2SNC M ,BEHAVIOR ,Solid solution - Abstract
Quasi phase-pure (>98 wt %) MAX phase solid solution ceramics with the (Zr,Ti)2(Al0.5,Sn0.5)C stoichiometry and variable Zr/Ti ratios were synthesized by both reactive hot pressing and pressureless sintering of ZrH2, TiH2, Al, Sn, and C powder mixtures. The influence of the different processing parameters, such as applied pressure and sintering atmosphere, on phase purity and microstructure of the produced ceramics was investigated. The addition of Sn to the (Zr,Ti)2AlC system was the key to achieve phase purity. Its effect on the crystal structure of a 211-type MAX phase was assessed by calculating the distortions of the octahedral M6C and trigonal M6A prisms due to steric effects. The M6A prismatic distortion values were found to be smaller in Sn-containing double solid solutions than in the (Zr,Ti)2AlC MAX phases. The coefficients of thermal expansion along the ⟨ a⟩ and ⟨ c⟩ directions were measured by means of Rietveld refinement of high-temperature synchrotron X-ray diffraction data of (Zr1- x,Ti x)2(Al0.5,Sn0.5)C MAX phase solid solutions with x = 0, 0.3, 0.7, and 1. The thermal expansion coefficient data of the Ti2(Al0.5,Sn0.5)C solid solution were compared with those of the Ti2AlC and Ti2SnC ternary compounds. The thermal expansion anisotropy increased in the (Zr,Ti)2(Al0.5,Sn0.5)C double solid solution MAX phases as compared to the Zr2(Al0.5,Sn0.5)C and Ti2(Al0.5,Sn0.5)C end-members. ispartof: INORGANIC CHEMISTRY vol:58 issue:10 pages:6669-6683 ispartof: location:United States status: published
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- 2019
12. CaLa2FeCoSbO9 and ALa2FeNiSbO9 (A = Ca, Sr, Ba): cation-ordered, inhomogeneous, ferrimagnetic perovskites
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Yawei Tang, Mylène Hendrickx, Peter D. Battle, Joke Hadermann, J. M. Cadogan, and Emily C. Hunter
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Diffraction ,Materials science ,Magnetic structure ,Neutron diffraction ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Magnetization ,Crystallography ,Chemistry ,Ferrimagnetism ,Materials Chemistry ,Ceramics and Composites ,Crystallite ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Polycrystalline samples of CaLa2FeCoSbO9 and ALa2FeNiSbO9 (A = Ca, Sr, Ba) have been prepared in solid-state reactions and studied by a combination of transmission electron microscopy, magnetometry, X-ray diffraction, neutron diffraction and Mossbauer spectroscopy. Diffraction and TEM showed that each shows 1:1 B-site ordering in which Co2+/Ni2+ and Sb5+ tend to occupy two distinct crystallographic sites while Fe3+ is distributed over both sites. While X-ray and neutron diffraction agreed that all four compositions are monophasic with space group P21/n, TEM revealed different levels of compositional inhomogeneity at the subcrystal scale, which, in the case of BaLa2FeNiSbO9, leads to the occurrence of both a P21/n and an I2/m phase. Magnetometry and neutron diffraction show that these perovskites are ferrimagnets with a G-type magnetic structure. Their relatively low magnetisation can be attributed to their inhomogeneity. This work demonstrates the importance of studying the microstructure of complex compositions.
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- 2020
13. An in-depth study of Sn substitution in Li-rich/Mn-rich NMC as a cathode material for Li-ion batteries
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Maria A. Kirsanova, Artem M. Abakumov, Andreas Paulus, Mylène Hendrickx, Dirk Lamoen, Marnik Bercx, Joke Hadermann, Marlies K. Van Bael, Olesia M. Karakulina, and An Hardy
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Inorganic Chemistry ,Chemistry ,Materials science ,Bond strength ,Transmission electron microscopy ,Doping ,Analytical chemistry ,Thermal stability ,Density functional theory ,Electrochemistry ,Redox ,Ion - Abstract
Layered Li-rich/Mn-rich NMC (LMR-NMC) is characterized by high initial specific capacities of more than 250 mA h g(-1), lower cost due to a lower Co content and higher thermal stability than LiCoO2. However, its commercialisation is currently still hampered by significant voltage fade, which is caused by irreversible transition metal ion migration to emptied Li positionsviatetrahedral interstices upon electrochemical cycling. This structural change is strongly correlated with anionic redox chemistry of the oxygen sublattice and has a detrimental effect on electrochemical performance. In a fully charged state, up to 4.8 Vvs.Li/Li+, Mn4+ is prone to migrate to the Li layer. The replacement of Mn4+ for an isovalent cation such as Sn4+ which does not tend to adopt tetrahedral coordination and shows a higher metal-oxygen bond strength is considered to be a viable strategy to stabilize the layered structure upon extended electrochemical cycling, hereby decreasing voltage fade. The influence of Sn4+ on the voltage fade in partially charged LMR-NMC is not yet reported in the literature, and therefore, we have investigated the structure and the corresponding electrochemical properties of LMR-NMC with different Sn concentrations. We determined the substitution limit of Sn4+ in Li1.2Ni0.13Co0.13Mn0.54-xSnxO2 by powder X-ray diffraction and transmission electron microscopy to be x approximate to 0.045. The limited solubility of Sn is subsequently confirmed by density functional theory calculations. Voltage fade for x= 0 andx= 0.027 has been comparatively assessed within the 3.00 V-4.55 V (vs.Li/Li+) potential window, from which it is concluded that replacing Mn4+ by Sn4+ cannot be considered as a viable strategy to inhibit voltage fade within this window, at least with the given restricted doping level.
- Published
- 2020
14. Preparation of the noncentrosymmetric ferrimagnetic phase <tex>La_{0.9}Ba_{0.1}Mn_{0.96}O_{2.43}$</tex> by topochemical reduction
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Thomas G. Parsons, P. Shiv Halasyamani, Michael A. Hayward, and Joke Hadermann
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Materials science ,Magnetism ,Neutron diffraction ,chemistry.chemical_element ,02 engineering and technology ,Manganese ,engineering.material ,010402 general chemistry ,01 natural sciences ,Inorganic Chemistry ,Ferrimagnetism ,Materials Chemistry ,Brownmillerite ,Antiferromagnetism ,Physical and Theoretical Chemistry ,Perovskite (structure) ,Magnetic structure ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Crystallography ,Chemistry ,chemistry ,Ceramics and Composites ,engineering ,0210 nano-technology - Abstract
Topochemical reduction of La0.9Ba0.1MnO3 with NaH at 225 degrees C yields the brownmillerite phase La0.9Ba0.1MnO2.5. However, reduction with CaH2 at 435 degrees C results in the formation of La0.9Ba0.1Mn0.96O2.43 via the deintercalation of both oxide anions and manganese cations from the parent perovskite phase. Electron and neutron diffraction data reveal La0.9Ba0.1Mn0.96O2.43 adopts a complex noncentrosymmetric structure, described in space group I23, confirmed by SHG measurements. Low-temperature neutron diffraction data reveal La0.9Ba0.1Mn0.96O2.43 adopts an ordered magnetic structure in which all the nearest neighbor interactions are antiferromagnetic. However, the presence of ordered manganese cation-vacancies results in a net ferrimagnetic structure with net saturated moment of 0.157(2) mu B per manganese center.
- Published
- 2020
15. High-temperature properties of (La,Ca)(Fe,Mg,Mo)O3-δ perovskites as prospective electrode materials for symmetrical SOFC
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Anatolii V. Morozov, E.V. Antipov, M.M. Abdullayev, S. Ya. Istomin, A. V. Sobolev, Joke Hadermann, S. M. Kazakov, Maria Batuk, and Igor A. Presniakov
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Materials science ,Analytical chemistry ,chemistry.chemical_element ,Mineralogy ,02 engineering and technology ,Electrolyte ,Conductivity ,010402 general chemistry ,01 natural sciences ,Oxygen ,Inorganic Chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry ,Perovskite (structure) ,Reducing atmosphere ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Chemistry ,chemistry ,Ceramics and Composites ,Solid oxide fuel cell ,Orthorhombic crystal system ,0210 nano-technology ,Stoichiometry - Abstract
La1-yCayFe0.5+x(Mg,Mo)(0.5-x)O3-delta oxides with the orthorhombic GdFeO3-type perovskite structure have been synthesized at 1573 K. Transmission electron microscopy study for selected samples shows the coexistence of domains of perovskite phases with ordered and disordered B-cations. Mossbauer spectroscopy studies performed at 300 K and 573 K show that while compositions with low Ca-content (La0.55Ca0.45Fe0.5Mg0.2625Mo0.2375O3-delta and La0.5Ca0.5Fe0.6Mg0.175Mo0.225O3-delta) are nearly oxygen stoichiometric, La0.2Ca0.8Fe0.5Mg0.2625Mo0.2375O3-delta is oxygen deficient with delta approximate to 0.15. Oxides are stable in reducing atmosphere (Ar/H-2, 8%) at 1173 K for 12 h. No additional phases have been observed at XRPD patterns of all studied perovskites and Ce1-xGdxO2-x/2 electrolyte mixtures treated at 1173-1373K, while Fe-rich compositions (x >= 0.1) react with Zr1-xYxO2-x/2 electrolyte above 1273 K. Dilatometry studies reveal that all samples show rather low thermal expansion coefficients (TECs) in air of 11.4-12.7 ppm K-1. In reducing atmosphere their TECs were found to increase up to 12.1-15.4 ppm K-1 due to chemical expansion effect. High-temperature electrical conductivity measurements in air and Ar/H-2 atmosphere show that the highest conductivity is observed for Fe- and Ca-rich compositions. Moderate values of electrical conductivity and TEC together with stability towards chemical interaction with typical SOFC electrolytes make novel Fe-containing perovskites promising electrode materials for symmetrical solid oxide fuel cell.
- Published
- 2018
16. Small-moment paramagnetism and extensive twinning in the topochemically reduced phase Sr2ReLiO5.5
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Michael A. Hayward, Joke Hadermann, Nicolas Gauquelin, Johan Verbeeck, Nijat Hasanli, and Inorganic Materials Science
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Materials science ,Magnetism ,Physics ,Stacking ,Oxide ,chemistry.chemical_element ,Rhenium ,010402 general chemistry ,01 natural sciences ,n/a OA procedure ,0104 chemical sciences ,Inorganic Chemistry ,Chemistry ,Magnetization ,Paramagnetism ,Crystallography ,chemistry.chemical_compound ,Electron diffraction ,chemistry ,0103 physical sciences ,010306 general physics ,Crystal twinning - Abstract
Reaction of the cation-ordered double perovskite Sr2ReLiO6 with dilute hydrogen at 475 °C leads to the topochemical deintercalation of oxide ions from the host lattice and the formation of a phase of composition Sr2ReLiO5.5, as confirmed by thermogravimetric and EELS data. A combination of neutron and electron diffraction data reveals the reduction process converts the –Sr2O2–ReLiO4–Sr2O2–ReLiO4– stacking sequence of the parent phase into a –Sr2O2–ReLiO3–Sr2O2–ReLiO4–, partially anion-vacant ordered sequence. Furthermore a combination of electron diffraction and imaging reveals Sr2ReLiO5.5 exhibits extensive twinning – a feature which can be attributed to the large, anisotropic volume expansion of the material on reduction. Magnetisation data reveal a strongly reduced moment of μeff = 0.505μB for the d1 Re6+ centres in the phase, suggesting there remains a large orbital component to the magnetism of the rhenium centres, despite their location in low symmetry coordination environments.
- Published
- 2018
17. Optimization of in situ 3D electron diffraction in an electrochemical liquid cell for crystal structure determination of energy materials
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Mylène Hendrickx and Joke Hadermann
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Inorganic Chemistry ,Structural Biology ,General Materials Science ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2021
18. Investigating structure transformations of La x Sr2−x MnO4−δ using in situ 3D electron diffraction in a gas environment
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Daphne Vandemeulebroucke, Maria Batuk, and Joke Hadermann
- Subjects
Inorganic Chemistry ,Structural Biology ,General Materials Science ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2021
19. Uncovering hidden complexity in oxygen-deficient perovskites
- Author
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Maria Batuk, Daphne Vandemeulebroucke, and Joke Hadermann
- Subjects
Inorganic Chemistry ,Structural Biology ,General Materials Science ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2021
20. Characterization of the correlated disorder in Ge2Bi4Te7
- Author
-
Matthias Quintelier, Stefano Canossa, Mylène Hendrickx, Romy Poppe, and Joke Hadermann
- Subjects
Inorganic Chemistry ,Structural Biology ,General Materials Science ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2021
21. Pb2NiOsO6: antiferromagnetic order breaks inversion symmetry in high-pressure perovskite
- Author
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Emma E. McCabe, Hai L. Feng, Chang-Jong Kang, Pascal Manuel, Fabio Orlandi, Yu Su, Jie Chen, Yoshihiro Tsujimoto, Joke Hadermann, Gabriel Kotliar, Kazunari Yamaura, and Martha Greenblatt
- Subjects
Inorganic Chemistry ,Structural Biology ,General Materials Science ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2021
22. Cobalt location in p-CoOx/n-SnO2 nanocomposites: Correlation with gas sensor performances
- Author
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S.A. Vladimirova, Marina Rumyantseva, Elizaveta A. Konstantinova, Olesia M. Karakulina, Alexander Gaskov, Joke Hadermann, A.S. Chizhov, V.F. Kozlovsky, A.V. Marchevsky, N. O. Khmelevsky, and D. G. Filatova
- Subjects
Materials science ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Crystallinity ,X-ray photoelectron spectroscopy ,Materials Chemistry ,Cobalt oxide ,Tin dioxide ,Physics ,Mechanical Engineering ,Metals and Alloys ,equipment and supplies ,021001 nanoscience & nanotechnology ,Tin oxide ,Cobalt sulfide ,0104 chemical sciences ,Chemistry ,chemistry ,Chemical engineering ,Mechanics of Materials ,0210 nano-technology ,Engineering sciences. Technology ,Cobalt ,Carbon monoxide - Abstract
Nanocomposites CoOx/SnO2 based on tin oxide powders with different crystallinity have been prepared by wet chemical synthesis and characterized in detail by ICP-MS, XPS, EPR, XRD, HAADF-STEM imaging and EDX-STEM mapping. It was shown that cobalt is distributed differently between the bulk and surface of SnO2 nanocrystals, which depends on the crystallinity of the SnO2 matrix. The measurements of gas sensor properties have been carried out during exposure to CO (10 ppm), and H2S (2 ppm) in dry air. The decrease of sensor signal toward CO was attributed to high catalytic activity of Co3O4 leading to oxidation of carbon monoxide entirely on the surface of catalyst particles. The formation of a p-CoOx/n-SnO2 heterojunction results in high sensitivity of nanocomposites in H2S detection. The conductance significantly changed in the presence of H2S, which was attributed to the formation of metallic cobalt sulfide and removal of the p - n junction. (C) 2017 Elsevier B.V. All rights reserved.
- Published
- 2017
23. Crystal Growth and Structure Analysis of Ce18W10O57: A Complex Oxide Containing Tungsten in an Unusual Trigonal Prismatic Coordination Environment
- Author
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Jeongho Yeon, T. Thao Tran, Joke Hadermann, Mark D. Smith, Hans-Conrad zur Loye, Dileka Abeysinghe, P. Shiv Halasyamani, and Robert Paria Sena
- Subjects
Chemistry ,Inorganic chemistry ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Trigonal prismatic molecular geometry ,01 natural sciences ,Magnetic susceptibility ,0104 chemical sciences ,Inorganic Chemistry ,Paramagnetism ,Cerium ,chemistry.chemical_compound ,Crystallography ,Tungstate ,Octahedron ,Oxidation state ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
The noncentrosymmetric tungstate oxide, Ce18W10O57) was synthesized for the first time as high-quality single crystals via the molten chloride flux method and structurally characterized by single-crystal X-ray diffraction. The compound is a structural analogue to the previously reported La18W10O57, which crystallizes in the hexagonal space group P (6) over bar 2c. The +3 oxidation state of cerium in Ce18W10O57 was achieved via the in situ reduction of Ce(IV) to Ce(III) using Zn metal. The structure consists of both isolated and face-shared WO6 octahedra and, surprisingly, isolated WO6 trigonal prisms. A careful analysis of the packing arrangement in the structure makes it possible to explain the unusual structural architecture of Ce18W10O57, which is described in detail. The temperature-dependent magnetic susceptibility of Ce18W10O57 indicates that the cerium(III) f(1) cations do not order magnetically and exhibit simple paramagnetic behavior. The SHG efficiency of Ln(18)W(10)O(57) (Ln = La, Ce) was measured as a function of particle size, and both compounds were found to be SHG active with efficiency approximately equal to that of alpha-SiO2.
- Published
- 2017
24. Stabilisation of magnetic ordering in <tex>La_{3}Ni_{2-x}Cu_{x}B'O_{9}(B'=Sb,Ta,Nb)$</tex> by the introduction of <tex>Cu^{2+}$</tex>
- Author
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Maxim Avdeev, Peter D. Battle, Mylène Hendrickx, Emily C. Hunter, Chun–Mann Chin, and Joke Hadermann
- Subjects
Materials science ,Magnetism ,Transition temperature ,Neutron diffraction ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,Inorganic Chemistry ,Magnetization ,Crystallography ,Chemistry ,Ferrimagnetism ,Transmission electron microscopy ,law ,Materials Chemistry ,Ceramics and Composites ,Physical and Theoretical Chemistry ,Electron microscope ,0210 nano-technology ,Perovskite (structure) - Abstract
La3Ni2-xCuxB'O-9 (x = 0.25; B' = Sb, Ta, Nb: x = 0.5; B' = Nb) have been synthesized and characterised by transmission electron microscopy, neutron diffraction and magnetometry. Each adopts a perovskite-like structure (space group P2(1)/n) with two crystallographically-distinct six-coordinate sites, one occupied by a disordered arrangement of Ni2+ and Cu2+ and the other by a disordered similar to 1:2 distribution of Ni2+ and B'(5+), although some Cu2+ is found on the latter site when x = 0.5. Each composition undergoes a magnetic transition in the range 90 = 30 K. A long-range ordered G-type ferrimagnetic structure is present in each composition, but small relaxor domains are also present. This contrasts with the pure relaxor and spin-glass behaviour of x = 0, B' = Ta, Nb, respectively.
- Published
- 2019
25. Toward unlocking the <tex>Mn^{3+}/Mn^{2+}$</tex> redox pair in alluaudite-type <tex>Na_{2+2z}Mn_{2-z}(SO_{4})_{3-x}(SeO_{4})_{x}$</tex> cathodes for sodium-ion batteries
- Author
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Olesia M. Karakulina, Artem M. Abakumov, An Hardy, Dries De Sloovere, Maria A. Kirsanova, Joke Hadermann, and Marlies K. Van Bael
- Subjects
Chemistry ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,Redox ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Metal ,Electronegativity ,Crystallography ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry ,Isostructural ,0210 nano-technology ,Inductive effect ,Solid solution - Abstract
In polyanion cathodes, the inductive effect alters the potential of a M(n+1)+/Mn+ redox couple (M - transition metal) according to the electronegativity of the X cation in the polyanion groups (XO4m+). To manipulate the operating potential, we synthesized a series of mixed sulfate-selenate alluaudites, with structure formulas Na2+2zMn2-z(SO4)(3-x)(SeO4)(x) and Na2.81Ni1.60(SO4)(1.43)(SeO4)(1.57). Their crystal structure was determined from powder X-ray diffraction data, revealing that the Mn-based alluaudites form solid solutions with the same crystal structure for x = 0.75; 1.125 and 1.5. Na2.81Ni1.60(SO4)(1.43)(SeO4)(1.57) is isostructural to the Mn-based alluaudites. Although the Na2+2zMn2-z(SO4)(3-x)(SeO4)(x) compound with the highest selenium content demonstrates a reversible discharge capacity of 60 mAh g(-1), only a small part of this electrochemical activity can be ascribed to the Mn3+/Mn2+ redox couple. The redox potential of the Mn3+/Mn2+ pair in Na2+2zMn2-z(SO4)(3-)x(SeO4)(x) decreases with increasing values of x, in agreement with the lower electronegativity of Se compared to that of S.
- Published
- 2019
26. Structural and magnetic properties of the perovskites A2LaFe2SbO9 (A = Ca, Sr, Ba)
- Author
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Mylène Hendrickx, Yawei Tang, Joke Hadermann, Emily C. Hunter, and Peter D. Battle
- Subjects
Neutron powder diffraction ,Materials science ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Crystallography ,Octahedron ,Transmission electron microscopy ,Phase (matter) ,Materials Chemistry ,Ceramics and Composites ,Crystallite ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Polycrystalline samples of A2LaFe2SbO9 (A = Ca, Sr, Ba) perovskites appeared monophasic to X-ray or neutron powder diffraction but a single-crystal study utilising transmission electron microscopy revealed a greater level of complexity. Although local charge balance is maintained, compositional and structural variations are present among and within the submicron-sized crystals. Despite the inhomogeneity, A = Ca is monophasic with a partially-ordered distribution of Fe3+ and Sb5+ cations across two crystallographically-distinct octahedral sites, i.e. Ca2La(Fe1.25Sb0.25)2d (Fe0.75Sb0.75)2cO9. For A = Sr or Ba, the inhomogeneities result in differences in the tilting patterns of the octahedra and the ordering of the B cations. Particles of A = Sr contain a phase (Fe:Sb ~2:1) without B cation ordering and one (Fe:Sb ~1:1) with B cation ordering. Monophasic A = Ba lacks long-range cation order although ordered nanodomains are present within the disordered phase. The temperature dependence of the magnetic properties of each sample is discussed.
- Published
- 2021
27. Mn2O3 oxide with bixbyite structure for the electrochemical oxygen reduction reaction in alkaline media: Highly active if properly manipulated
- Author
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Anna S. Ryabova, Joke Hadermann, Sergey Ya. Istomin, N. A. Arkharova, Galina A. Tsirlina, Elena R. Savinova, Viktoriia A. Saveleva, Evgeny V. Antipov, Anton S. Orekhov, Robert Paria Sena, Gwénaëlle Kéranguéven, Antoine Bonnefont, Kirill A. Dosaev, Institut de Chimie de Strasbourg, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Université Louis Pasteur - Strasbourg I-Institut de Chimie du CNRS (INC), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,General Chemical Engineering ,Inorganic chemistry ,Oxide ,[CHIM.CATA]Chemical Sciences/Catalysis ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Bixbyite ,Electrochemistry ,01 natural sciences ,Redox ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Reversible hydrogen electrode ,Cyclic voltammetry ,Rotating disk electrode ,0210 nano-technology ,ComputingMilieux_MISCELLANEOUS - Abstract
We consider compositional and structural factors which can affect the activity of bixbyite α-Mn2O3 towards the oxygen reduction reaction (ORR) and the stability of this oxide in alkaline solution. We compare electrochemistry of undoped, Fe and Al-doped α-Mn2O3 with bixbyite structure and braunite Mn7SiO12 having bixbyite-related crystal structure, using the rotating disk electrode (RDE), the rotating ring-disk electrode (RRDE), and cyclic voltammetry (CV) techniques. All manganese oxides under study are stable in the potential range between the ORR onset and ca. 0.7 V vs. Reversible Hydrogen Electrode (RHE). It is found that any changes introduced in the bixbyite structure and/or composition of α-Mn2O3 lead to an activity drop in both the oxygen reduction and hydrogen peroxide reactions in this potential interval. For the hydrogen peroxide reduction reaction these modifications also result in a change in the nature of the rate-determining step. The obtained results confirm that due to its unique crystalline structure undoped α-Mn2O3 is the most ORR active (among currently available) Mn oxide catalyst and favor the assumption of the key role of the (111) surface of α-Mn2O3 in the very high activity of this material towards the ORR.
- Published
- 2021
28. Complex Microstructure and Magnetism in Polymorphic CaFeSeO
- Author
-
Simon J. Clarke, Daniel N. Woodruff, Dmitry Batuk, Maria Batuk, Amber L. Thompson, Joke Hadermann, and Simon J. Cassidy
- Subjects
Chemistry ,Magnetism ,Physics ,Oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Magnetic susceptibility ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,Ferromagnetism ,Selenide ,Tetrahedron ,Antiferromagnetism ,Physical and Theoretical Chemistry ,0210 nano-technology ,Néel temperature - Abstract
The structural complexity of the antiferromagnetic oxide selenide CaFeSeO is described. The compound contains puckered FeSeO layers composed of FeSe2O2 tetrahedra sharing all their vertexes. Two polymorphs coexist that can be derived from an archetype BaZnSO structure by cooperative tilting of the FeSe2O2 tetrahedra. The polymorphs differ in the relative arrangement of the puckered layers of vertex-linked FeSe2O2 tetrahedra. In a noncentrosymmetric Cmc21 polymorph (a = 3.89684(2) Å, b = 13.22054(8) Å, c = 5.93625(2) Å) the layers are related by the C-centering translation, while in a centrosymmetric Pmcn polymorph, with a similar cell metric (a = 3.89557(6) Å, b = 13.2237(6) Å, c = 5.9363(3) Å), the layers are related by inversion. The compound shows long-range antiferromagnetic order below a Neél temperature of 159(1) K with both polymorphs showing antiferromagnetic coupling via FeOFe linkages and ferromagnetic coupling via FeSeFe linkages within the FeSeO layers. The magnetic susceptibility also shows evidence for weak ferromagnetism which is modeled in the refinements of the magnetic structure as arising from an uncompensated spin canting in the noncentrosymmetric polymorph. There is also a spin glass component to the magnetism which likely arises from the disordered regions of the structure evident in the transmission electron microscopy.
- Published
- 2016
29. Synthesis, structure and electrochemical properties of LiNaCo0.5Fe0.5PO4F fluoride-phosphate
- Author
-
Oleg A. Drozhzhin, Sergey M. Kuzovchikov, Joke Hadermann, Artem M. Abakumov, Nellie R. Khasanova, D. S. Filimonov, Evgeny V. Antipov, Olesia M. Karakulina, and Stanislav S. Fedotov
- Subjects
Chemistry ,Physics ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,Redox ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Crystallography ,Electron diffraction ,Transition metal ,Oxidation state ,Mössbauer spectroscopy ,Materials Chemistry ,Ceramics and Composites ,Physical chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology ,High-resolution transmission electron microscopy - Abstract
LiNaCo 0.5 Fe 0.5 PO 4 F fluoride-phosphate was synthesized via conventional solid-state and novel freeze-drying routes. The crystal structure was refined based on neutron powder diffraction (NPD) data and validated by electron diffraction (ED) and high-resolution transmission electron microscopy (HRTEM). The alkali ions are ordered in LiNaCo 0.5 Fe 0.5 PO 4 F and the transition metals jointly occupy the same crystallographic sites. The oxidation state and oxygen coordination environment of the Fe atoms were verified by 57 Fe Mossbauer spectroscopy. Electrochemical tests of the LiNaCo 0.5 Fe 0.5 PO 4 F cathode material demonstrated a reversible activity of the Fe 3+ /Fe 2+ redox couple at the electrode potential near 3.4 V and minor activity of the Co 3+ /Co 2+ redox couple over 5 V vs Li/Li + . The material exhibited the discharge capacity of more than 82% (theo.) regarding Fe 3+ /Fe 2+ in the 2.4÷4.6 V vs Li/Li + potential range.
- Published
- 2016
30. Ba3(Cr0.97(1)Te0.03(1))2TeO9: in Search of Jahn–Teller Distorted Cr(II) Oxide
- Author
-
Carlo U. Segre, Peter W. Stephens, David Walker, Man-Rong Li, Zheng Deng, Joke Hadermann, Saul H. Lapidus, Robert Paria Sena, Mark Croft, and Martha Greenblatt
- Subjects
Diffraction ,Valence (chemistry) ,Jahn–Teller effect ,Oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Chemistry ,Crystallography ,chemistry.chemical_compound ,Paramagnetism ,chemistry ,Octahedron ,Transmission electron microscopy ,Physical and Theoretical Chemistry ,0210 nano-technology ,Spectroscopy - Abstract
A novel 6H-type hexagonal perovskite Ba-3(Cr0.97(1)Te0.03(1))(2)TeO9 was prepared at high pressure (6 GPa) and temperature (1773 K). Both transmission electron microscopy and synchrotron powder X-ray diffraction data demonstrate that Ba-3(Cr0.97(1)Te0.03(1))(2)TeO9 crystallizes in P6(3)/mmc with face-shared (Cr0.97(1)Te0.03(1))O-6 octahedral pairs interconnected with TeO6 octahedra via corner-sharing. Structure analysis shows a mixed Cr2+/Cr3+ valence state with similar to 10% Cr2+. The existence of Cr2+ in Ba-3(Cr0.10(1)2+Cr0.87(1)3+Te0.036+)(2)TeO9 is further evidenced by X-ray absorption near-edge spectroscopy. Magnetic properties measurements show a paramagnetic response down to 4 K and a small glassy-state curvature at low temperature. In this work, the octahedral Cr2+O6 component is stabilized in an oxide material for the first time; the expected Jahn-Teller distortion of high-spin (d(4)) Cr2+ is not found, which is attributed to the small proportion of Cr2+ (similar to 10%) and the face-sharing arrangement of CrO6 octahedral pairs, which structurally disfavor axial distortion.
- Published
- 2016
31. Study of Hydrogen Peroxide Reactions on Manganese Oxides as a Tool To Decode the Oxygen Reduction Reaction Mechanism
- Author
-
Anna S. Ryabova, Evgeny V. Antipov, Sergey Ya. Istomin, Galina A. Tsirlina, Gwénaëlle Kéranguéven, Pavel A. Zagrebin, Elena R. Savinova, Robert Paria Sena, Artem M. Abakumov, Tiphaine Poux, Joke Hadermann, and Antoine Bonnefont
- Subjects
Chemistry ,Physics ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,Reaction intermediate ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,Photochemistry ,01 natural sciences ,Decomposition ,Oxygen ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Elementary reaction ,Reactivity (chemistry) ,0210 nano-technology ,Hydrogen peroxide - Abstract
Hydrogen peroxide has been detected as a reaction intermediate in the electrochemical oxygen reduction reaction (ORR) on transition-metal oxides and other electrode materials. In this work, we studied the electrocatalytic and catalytic reactions of hydrogen peroxide on a set of Mn oxides, Mn2O3, MnOOH, LaMnO3, MnO2, and Mn3O4, that adopt different crystal structures to shed light on the mechanism of the ORR on these materials. We then combined experiment with kinetic modeling with the objective to correlate the differences in the ORR activity to the kinetics of the elementary reaction steps, and we uncovered the importance of structural and compositional factors in the catalytic activity of the Mn oxides. We concluded that the exceptional activity of Mn2O3 in the ORR is due to its high catalytic activity both in the reduction of oxygen to hydrogen peroxide and in the decomposition of the latter, and furthermore, we proposed a tentative link between crystal structure and reactivity.
- Published
- 2016
32. Layered-to-Tunnel Structure Transformation and Oxygen Redox Chemistry in LiRhO2 upon Li Extraction and Insertion
- Author
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Lars Giebeler, Helmut Ehrenberg, J. Eckert, Daria Mikhailova, Dmitry Batuk, Steffen Oswald, Alexander A. Tsirlin, Michael Knapp, Markus Herklotz, Olesia M. Karakulina, Artem M. Abakumov, Marcus Schmidt, and Joke Hadermann
- Subjects
Physics ,Intercalation (chemistry) ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Oxygen ,Redox ,0104 chemical sciences ,Ion ,Inorganic Chemistry ,Crystallography ,Transition metal ,chemistry ,ddc:540 ,Electrode ,Physical and Theoretical Chemistry ,Isostructural ,0210 nano-technology - Abstract
Inorganic chemistry 55(14), 7079 - 7089(2016). doi:10.1021/acs.inorgchem.6b01008, Layered Li(M,Li)O$_{2}$ (where M is a transition metal) ordered rock-salt-type structures are used in advanced metal-ion batteries as one of the best hosts for the reversible intercalation of Li ions. Besides the conventional redox reaction involving oxidation/reduction of the M cation upon Li extraction/insertion, creating oxygen-located holes because of the partial oxygen oxidation increases capacity while maintaining the oxidized oxygen species in the lattice through high covalency of the M−O bonding. Typical degradation mechanism of the Li(M,Li)O$_{2}$ electrodes involves partially irreversible M cation migration toward the Li positions, resulting in gradual capacity/voltage fade. Here, using LiRhO$_{2}$as a model system (isostructural and isoelectronic to LiCoO$_{2}$), for the first time, we demonstrate an intimate coupling between the oxygen redox and M cation migration. A formation of the oxidized oxygen species upon electrochemical Li extraction coincides with transformation of the layered Li$_{1−x}$RhO$_{2}$ structure into the $\gamma$-MnO$_{2}$-type rutile−ramsdellite intergrowth LiyRh3O6 structure with rutile-like [1 × 1] channels along with bigger ramsdellite-like [2 × 1] tunnels through massive and concerted Rh migration toward the empty positions in the Li layers. The oxidized oxygen dimers with the O−O distances as short as 2.26 Å are stabilized in this structure via the local Rh−O configuration reminiscent to that in the $\mu$-peroxo-$\mu$-hydroxo Rh complexes. The Li$_y$Rh$_3$O$_6$ structure is remarkably stable upon electrochemical cycling illustrating that proper structural implementation of the oxidized oxygen species can open a pathway toward deliberate employment of the anion redox chemistry in high-capacity/high-voltage positive electrodes for metal-ion batteries., Published by American Chemical Society, Washington, DC
- Published
- 2016
33. Sensitivity of nanocrystalline tungsten oxide to CO and ammonia gas determined by surface catalysts
- Author
-
Artem Marikutsa, Maria Batuk, Marina Rumyantseva, Joke Hadermann, Alexander Gaskov, and Lili Yang
- Subjects
Materials science ,Inorganic chemistry ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,Ammonia ,chemistry.chemical_compound ,Crystallinity ,Materials Chemistry ,Electrical and Electronic Engineering ,Instrumentation ,Deposition (law) ,Aqueous solution ,Physics ,Metals and Alloys ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Nanocrystalline material ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemistry ,chemistry ,Surface modification ,Particle size ,0210 nano-technology - Abstract
Nanocrystalline tungsten oxide with variable particle size and surface area was synthesized by aqueous deposition and heat treatment for use in resistive gas sensors. Surface modification with 1 wt.% Pd and Ru was performed by impregnation to improve the sensitivity to CO and ammonia. Acid and oxidation surface sites were evaluated by temperature-programmed techniques using probe molecules. The surface acidity dropped with increasing particle size, and was weakly affected by additives. Lower crystallinity of WO3 and the presence of Ru species favoured temperature-programmed reduction of the materials. Modifying WO3 increased its sensitivity, to CO at ambient condition for modification by Pd and to NH3 at elevated temperature for Ru modification. An in situ infrared study of the gas – solid interaction showed that the catalytic additives change the interaction route of tungsten oxide with the target gases and make the reception of detected molecules independent of the semiconductor oxide matrix.
- Published
- 2018
34. Ferrimagnetism as a consequence of unusual cation ordering in the Perovskite <tex>SrLa_{2}FeCoSbO_{9}$</tex>
- Author
-
Joke Hadermann, Mylène Hendrickx, Yawei Tang, Emily C. Hunter, J. M. Cadogan, and Peter D. Battle
- Subjects
Magnetic moment ,Chemistry ,Neutron diffraction ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Crystallography ,Remanence ,Ferrimagnetism ,Formula unit ,Diamagnetism ,Physical and Theoretical Chemistry ,0210 nano-technology ,Monoclinic crystal system - Abstract
A polycrystalline sample of SrLa2FeCoSbO9 has been prepared in a solid-state reaction and studied by a combination of electron microscopy, magnetometry, Mossbauer spectroscopy, X-ray diffraction, and neutron diffraction. The compound adopts a monoclinic (space group P2(1)/n; a = 5.6218(6), b = 5.6221(6), c = 7.9440(8) angstrom, beta = 90.050(7)degrees at 300 K) perovskite-like crystal structure with two crystallographically distinct six-coordinate sites. One of these sites is occupied by 2/3 Co-2(+),1/3 Fe3+ and the other by 2/3 Sb5+, 1/3 Fe3+. This pattern of cation ordering results in a transition to a ferrimagnetic phase at 215 K. The magnetic moments on nearest-neighbor, six-coordinate cations align in an antiparallel manner, and the presence of diamagnetic Sb5+ on only one of the two sites results in a nonzero remanent magnetization of similar to 1 mu(B) per formula unit at 5 K.
- Published
- 2018
35. P1GS.5 - Sensitivity of Nanocrystalline Metal Oxides to CO and Ammonia Determined by Active Sites
- Author
-
Artem Marikutsa, Dirk Lamoen, Maria Batuk, Alexander Gaskov, Joke Hadermann, Marina Rumyantseva, and L. Yang
- Subjects
Metal ,Ammonia ,chemistry.chemical_compound ,Materials science ,chemistry ,visual_art ,Inorganic chemistry ,visual_art.visual_art_medium ,Sensitivity (control systems) ,Nanocrystalline material - Published
- 2018
36. Effect of bimetallic Pd/Pt clusters on the sensing properties of nanocrystalline <tex>SnO_{2}$</tex> in the detection of CO
- Author
-
Andrey V. Zadesenets, Artem Marikutsa, V. V. Krivetskii, I. Malkov, Joke Hadermann, Alexander Gaskov, D. I. Potemkin, Marina Rumyantseva, and Maria Batuk
- Subjects
Materials science ,Hydrogen ,Tin dioxide ,Materials Science (miscellaneous) ,Analytical chemistry ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Microanalysis ,Nanocrystalline material ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Chemistry ,chemistry ,Transmission electron microscopy ,Physical and Theoretical Chemistry ,0210 nano-technology ,Platinum ,Bimetallic strip - Abstract
Nanocrystalline tin dioxide modified by Pd and Pt clusters or by bimetallic PdPt nanoparticles was synthesized. Distribution of the modifers on the SnO2 surface was studied by high-resolution transmission electron microscopy and energy dispersive X-ray microanalysis with element distribution mapping. It was shown that the Pd/Pt ratio in bimetallic particles varies over a broad range and does not depend on the particle diameter. The effect of platinum metals on the reducibility of nanocrystalline SnO2 by hydrogen was determined. The sensing properties of the resulting materials towards 6.7 ppm CO in air were estimated in situ by electrical conductivity measurements. The sensor response of SnO2 modified with bimetallic PdPt particles was a superposition of the signals of samples with Pt and Pd clusters.
- Published
- 2018
37. Comparative study of the magnetic properties of La3Ni2B'O9 for B' = Nb, Ta or Sb
- Author
-
Mylène Hendrickx, Peter D. Battle, Stephen J. Blundell, Franz Lang, Chun-Mann Chin, Emily C. Hunter, Robert Paria Sena, and Joke Hadermann
- Subjects
Materials science ,Spin glass ,Condensed matter physics ,Neutron diffraction ,Relaxation (NMR) ,Bragg's law ,02 engineering and technology ,Muon spin spectroscopy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Chemistry ,Materials Chemistry ,Ceramics and Composites ,Crystallite ,Physical and Theoretical Chemistry ,0210 nano-technology ,Monoclinic crystal system - Abstract
Polycrystalline samples of La3Ni2NbO9 and La3Ni2TaO9 have been characterised by X-ray and neutron diffraction, electron microscopy, magnetometry and muon spin relaxation (µSR); the latter technique was also applied to La3Ni2SbO9. On the length scale of a neutron diffraction experiment, the six-coordinate sites of the monoclinic perovskite structure are occupied in a 1:1 ordered manner by Ni and a random ⅓Ni/⅔B’ mixture. Electron microscopy demonstrated that this 1:1 ordering is maintained over microscopic distances, although diffuse scattering indicative of short-range ordering on the mixed site was observed. No magnetic Bragg scattering was observed in neutron diffraction patterns collected from La3Ni2B’O9(B’ = Nb or Ta) at 5 K although in each case µSR identified the presence of static spins below 30 K. Magnetometry showed that La3Ni2NbO9 behaves as a spin glass below 29 K but significant short-range interactions are present in La3Ni2TaO9 below 85 K. The contrasting properties of these compounds are discussed in terms of their microstructure.
- Published
- 2017
38. The interplay of microstructure and magnetism in La 3 Ni 2 SbO 9
- Author
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Maxim Avdeev, Joke Hadermann, and Peter D. Battle
- Subjects
Materials science ,Condensed matter physics ,Magnetic moment ,Magnetism ,Neutron diffraction ,Condensed Matter Physics ,Ferroelectricity ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Inorganic Chemistry ,Chemistry ,Magnetization ,Crystallography ,Ferrimagnetism ,Materials Chemistry ,Ceramics and Composites ,Physical and Theoretical Chemistry ,Perovskite (structure) - Abstract
La{sub 3}Ni{sub 2}SbO{sub 9} adopts a perovskite-related structure in which the six-coordinate cation sites are occupied alternately by Ni{sup 2+} and a disordered arrangement of Ni{sup 2+}/Sb{sup 5+}. A polycrystalline sample has been studied by neutron diffraction in applied magnetic fields of 0≤H/kOe≤50 at 5 K. In 0 kOe, weak magnetic Bragg scattering consistent with the adoption of a G-type ferrimagnetic structure is observed; the ordered component of the magnetic moment was found to be 0.89(7) µ{sub B} per Ni{sup 2+} cation. This increased to 1.60(3) µ{sub B} in a field of 50 kOe. Transmission electron microscopy revealed variations in the Ni:Sb ratio across crystallites of the sample. It is proposed that these composition variations disrupt the magnetic superexchange interactions within the compound, leading to domain formation and a reduced average moment. The application of a magnetic field aligns the magnetisation vectors across the crystal and the average moment measured by neutron diffraction increases accordingly. The role played by variations in the local chemical composition in determining the magnetic properties invites comparison with the behaviour of relaxor ferroelectrics. - Graphical abstract: Composition variations across a crystal of La3Ni2SbO9 result in anomalous magnetic behavior. - Highlights: • Ordered magnetic moment ofmore » Ni{sup 2+} increases in an applied magnetic field. • Composition variations detected by electron microscopy. • Increase in magnetic moment can be explained by presence of composition variations.« less
- Published
- 2014
39. Crystal structure study of manganese and titanium substituted BaLaFe 2 O 6-δ
- Author
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Maria Batuk, Ahmed Ben Hafsia, Mylène Hendrickx, Mohamed Khitouni, Jean-Marc Greneche, Joke Hadermann, N. Rammeh, University of Antwerp (UA), Electron Microscopy for Materials Science - EMAT (Antwerp, Belgium), Universiteit Antwerpen [Antwerpen], Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physico-Chimique des Matériaux Minéraux et leurs Applications, Borj Cedrea, Tunisia, Laboratoire de Physico-Chimique des Matériaux Minéraux et leurs Applications, and Institut Supérieur des Sciences et Technologies de l'Environnement de Borj Cédria - ISSTE (TUNISIA)-Institut Supérieur des Sciences et Technologies de l'Environnement de Borj Cédria - ISSTE (TUNISIA)
- Subjects
Materials science ,Reflection high-energy electron diffraction ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,01 natural sciences ,Inorganic Chemistry ,Scanning transmission electron microscopy ,Materials Chemistry ,Physical and Theoretical Chemistry ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,ComputingMilieux_MISCELLANEOUS ,Perovskite (structure) ,[PHYS]Physics [physics] ,Physics ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Chemistry ,Crystallography ,Electron diffraction ,X-ray crystallography ,Ceramics and Composites ,0210 nano-technology ,Powder diffraction ,Electron backscatter diffraction - Abstract
Barium lanthanum ferrite and four Mn/Ti substituted materials were synthesized by the sol-gel method. The crystal structure of the materials was studied by a combination of X-ray powder diffraction, electron diffraction, scanning transmission electron microscopy and 57Fe Mössbauer spectrometry. BaLaFe2O6-δ has a cubic perovskite structure and Ba0.7La1.3FeMnO6-δ is distorted perovskite with the R View the MathML source3̅c symmetry, both from electron diffraction and X-ray powder diffraction. However, according to transmission electron microscopy, the crystals of BaLaFeTiO6-δ, BaLaFeTi0.5Mn0.5O6-δ, and BaLaFe0.5Ti0.5MnO6-δ consist of nanodomains with different symmetries (Pm View the MathML source3̅m next to R View the MathML source3̅c due to octahedral tilts), whereas the bulk X-ray powder diffraction patterns for these compounds correspond to the simple cubic structure. 57Fe Mössbauer spectrometry confirms that all materials contain high spin state Fe3+ ions which are strongly influenced by the chemical disorder resulting from various cationic environments.
- Published
- 2017
40. Crystal structure, defects, magnetic and dielectric properties of the layered <tex>Bi_{3n+1}Ti_{7}Fe_{3n-3}O_{9n+11}$</tex> perovskite-anatase intergrowths
- Author
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Dmitry S. Filimonov, Olga S. Volkova, Oleg A. Tyablikov, Artem M. Abakumov, K. V. Zakharov, Alexander N. Vasiliev, Joke Hadermann, Dmitry Batuk, and Maria Batuk
- Subjects
Anatase ,Chemistry ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Crystallography ,Octahedron ,Mössbauer spectroscopy ,Orthorhombic crystal system ,Physical and Theoretical Chemistry ,0210 nano-technology ,Lone pair ,Monoclinic crystal system ,Perovskite (structure) - Abstract
The Bi3n+1Ti7Fe3n-3,O9n+11 materials are built of (001)(p) plane parallel perovskite blocks with a thickness of n (Ti,Fe)O-6 octahedra, separated by periodic translational interfaces. The interfaces are based on anatase-like chains of edge -sharing (Ti,Fe)O-6 octahedra. Together with the octahedra of the perovskite blocks, they create S-shaped tunnels stabilized by lone pair Bi3+ cations. In this work, the structure of the n = 4-6 Bi3n+1Ti7Fe3n-3,O9n+11 homologues is analyzed in detail using advanced transmission electron microscopy, powder X-ray diffraction, and Mossbauer spectroscopy. The connectivity of the anatase-like chains to the perovskite blocks results in,a 3ap periodicity along the interfaces, so that they can be located either on top of each other or with shifts of +/- a(p) along [100](p). The ordered arrangement of the interfaces gives rise to orthorhombic Immm and monoclinic A2/m polymorphs with the unit cell parameters a = 3a(p), b = b(p), c = 2(n + 1)c(p) and a = 3a(p), b = b(p), c = 2(n + 1)c(p) - a(p), respectively. While the n = 3 compound is orthorhombic, the monoclinic modification is more favorable in higher homologues. The Bi3n+1Ti7Fe3n-3,O9n+11 structures demonstrate intricate patterns of atomic displacements in the perovskite blocks, which are supported by the stereochemical activity of the Bi3+ cations. These patterns are coupled to the cationic coordination of the oxygen atoms in the (Ti,Fe)O-2 layers at the border of the perovskite blocks. The coupling is strong in the 1/ = 3, 4 homologues, but gradually reduces with the increasing thickness of the perovskite blocks, so that, in the n = 6 compound, the dominant mode of atomic displacements is aligned along the interface planes. The displacements in the adjacent perovskite blocks tend to order antiparallel, resulting in an overall antipolar structure. The Bi3n+1Ti7Fe3n-3,O9n+11 materials demonstrate an unusual diversity of structure defects. The n = 4-6 homologues are robust antiferromagnets below T-N = 135, 220, and 295 K, respectively. They show a high dielectric constant that weakly increases with temperature and is relatively insensitive to the Ti/Fe ratio.
- Published
- 2017
41. Pb5Fe3TiO11Cl: A rare example of Ti(IV) in a square pyramidal oxygen coordination
- Author
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Artem M. Abakumov, Dmitry Batuk, Maria Batuk, and Joke Hadermann
- Subjects
Materials science ,Magnetic structure ,Physics ,Condensed Matter Physics ,Dark field microscopy ,Square pyramidal molecular geometry ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Crystal ,Chemistry ,Crystallography ,Electron diffraction ,Scanning transmission electron microscopy ,Materials Chemistry ,Ceramics and Composites ,Physical and Theoretical Chemistry ,Powder diffraction ,Perovskite (structure) - Abstract
A new oxychloride Pb5Fe3TiO11Cl has been synthesized using the solid state method. Its crystal and magnetic structure was investigated in the 1.5–550 K temperature range using electron diffraction, high angle annular dark field scanning transmission electron microscopy, atomic resolution energy dispersive X-ray spectroscopy, neutron and X-ray powder diffraction. At room temperature Pb5Fe3TiO11Cl crystallizes in the P4/mmm space group with the unit cell parameters a=3.91803(3) A and c=19.3345(2) A. Pb5Fe3TiO11Cl is a new n=4 member of the oxychloride perovskite-based homologous series An+1BnO3n−1Cl. The structure is built of truncated Pb3Fe3TiO11 quadruple perovskite blocks separated by CsCl-type Pb2Cl slabs. The perovskite blocks consist of two layers of (Fe,Ti)O6 octahedra sandwiched between two layers of (Fe,Ti)O5 square pyramids. The Ti4+ cations are preferentially located in the octahedral layers, however, the presence of a noticeable amount of Ti4+ in a five-fold coordination environment has been undoubtedly proven using neutron powder diffraction and atomic resolution compositional mapping. Pb5Fe3TiO11Cl is antiferromagnetically ordered below 450(10) K. The ordered Fe magnetic moments at 1.5 K are 4.06(4) μB and 3.86(5) μB on the octahedral and square-pyramidal sites, respectively.
- Published
- 2014
42. Atomic Structure of Defects in Anion-Deficient Perovskite-Based Ferrites with a Crystallographic Shear Structure
- Author
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Gustaaf Van Tendeloo, Stuart Turner, Joke Hadermann, Artem M. Abakumov, Dmitry Batuk, and Maria Batuk
- Subjects
Diffraction ,Chemistry ,Physics ,Coordination number ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Homologous series ,chemistry.chemical_compound ,Crystallography ,Tetragonal crystal system ,Octahedron ,Transmission electron microscopy ,Physical and Theoretical Chemistry ,0210 nano-technology ,Perovskite (structure) - Abstract
Crystallographic shear (CS) planes provide a new structure-generation mechanism in the anion-deficient perovskites containing lone-pair cations. Pb2Sr2Bi2Fe6O16, a new n = 6 representative of the A(n)B(n)O(3n-2) homologous series of the perovskite-based ferrites with the CS structure, has been synthesized using the solid-state technique. The structure is built of perovskite blocks with a thickness of four FeO6 octahedra spaced by double columns of FeO5 edge-sharing distorted tetragonal pyramids, forming 1/2[110](101)p CS planes (space group Pnma, a = 5.6690(2) Å, b = 3.9108(1) Å, c = 32.643(1) Å). Pb2Sr2Bi2Fe6O16 features a wealth of microstructural phenomena caused by the flexibility of the CS planes due to the variable ratio and length of the constituting fragments with {101}p and {001}p orientation. This leads to the formation of "waves", "hairpins", "Γ-shaped" defects, and inclusions of the hitherto unknown layered anion-deficient perovskites Bi2(Sr,Pb)Fe3O8.5 and Bi3(Sr,Pb)Fe4O11.5. Using a combination of diffraction, imaging, and spectroscopic transmission electron microscopy techniques this complex microstructure was fully characterized, including direct determination of positions, chemical composition, and coordination number of individual atomic species. The complex defect structure makes these perovskites particularly similar to the CS structures in ReO3-type oxides. The flexibility of the CS planes appears to be a specific feature of the Sr-based system, related to the geometric match between the SrO perovskite layers and the {100}p segments of the CS planes.
- Published
- 2014
43. Polar and Magnetic Layered A-Site and Rock Salt B-Site-Ordered NaLnFeWO6 (Ln = La, Nd) Perovskites
- Author
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S. Chi, Martha Greenblatt, Mark Croft, Joachim Hemberger, Man-Rong Li, Walid Dachraoui, Jason P. Hodges, T. Thao Tran, Alexander Ignatov, Joke Hadermann, Christoph P. Grams, P. Shiv Halasyamani, Maria Retuerto, and Kandalam V. Ramanujachary
- Subjects
Diffraction ,Magnetic structure ,Chemistry ,Neutron diffraction ,Dielectric ,Crystal structure ,Inorganic Chemistry ,Condensed Matter::Materials Science ,Crystallography ,Electron diffraction ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Physical and Theoretical Chemistry ,Monoclinic crystal system - Abstract
We have expanded the double perovskite family of materials with the unusual combination of layered order in the A sublattice and rock salt order over the B sublattice to compounds NaLaFeWO6 and NaNdFeWO6. The materials have been synthesized and studied by powder X-ray diffraction, neutron diffraction, electron diffraction, magnetic measurements, X-ray absorption spectroscopy, dielectric measurements, and second harmonic generation. At room temperature, the crystal structures of both compounds can be defined in the noncentrosymmetric monoclinic P2(1) space group resulting from the combination of ordering both in the A and B sublattices, the distortion of the cell due to tilting of the octahedra, and the displacement of certain cations. The magnetic studies show that both compounds are ordered antiferromagnetically below T-N approximate to 25 K for NaLaFeWO6 and at similar to 21 K for NaNdFeWO6. The magnetic structure of NaNdFeWO6 has been solved with a propagation vector k = (1/2 0 1/2) as an antiferromagnetic arrangement of Fe and Nd moments. Although the samples are potential multiferroics, the dielectric measurements do not show a ferroelectric response.
- Published
- 2013
44. Polar and Magnetic Mn2FeMO6(M=Nb, Ta) with LiNbO3-type Structure: High-Pressure Synthesis
- Author
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Peter W. Stephens, P. Shiv Halasyamani, Joachim Hemberger, Man-Rong Li, David Walker, Maria Retuerto, Tapati Sarkar, Swarnakamal Mukherjee, Martha Greenblatt, Tanusri Saha Dasgupta, Alexander Ignatov, Christoph P. Grams, T. Thao Tran, Joke Hadermann, Mark Croft, and Israel Nowik
- Subjects
Steric effects ,Chemistry ,Inorganic chemistry ,General Medicine ,General Chemistry ,Type (model theory) ,Ferroelectricity ,Piezoelectricity ,Catalysis ,Pyroelectricity ,Chemical physics ,Polar ,High harmonic generation ,Multiferroics - Abstract
Polar oxides are of much interest in materials science and engineering. Their symmetry-dependent properties such as ferroelectricity/multiferroics, piezoelectricity, pyroelectricity, and second-order harmonic generation (SHG) effect are important for technological applications. [1] However, polar crystal design and synthesis is challenging, because multiple effects, such as steric or dipole-dipole interactions, typically combine to form non-polar structures; so the number of known polar materials, especially polar magnetoelectric materials, is still severely restricted. [2] Therefore, it is necessary for the material science community to develop new strategies to create these materials.
- Published
- 2013
45. Structural and Magnetic Phase Transitions in the AnBnO3n–2 Anion-Deficient Perovskites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16
- Author
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Dmitry S. Filimonov, Marina G. Rozova, Konstantin V. Pokholok, Denis Sheptyakov, Artem M. Abakumov, Joke Hadermann, Alexander A. Tsirlin, Oleg A. Tyablikov, V. S. Zhidal, Maria Batuk, Evgeny V. Antipov, and G. Van Tendeloo
- Subjects
Structural phase ,Chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Ion ,Inorganic Chemistry ,Tetragonal crystal system ,Crystallography ,Homologous series ,chemistry.chemical_compound ,Octahedron ,Magnetic phase ,Physical and Theoretical Chemistry ,0210 nano-technology ,Perovskite (structure) - Abstract
Novel anion-deficient perovskite-based ferrites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 were synthesized by solid-state reaction in air. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 belong to the perovskite-based AnBnO3n–2 homologous series with n = 5 and 6, respectively, with a unit cell related to the perovskite subcell ap as ap√2 × ap × nap√2. Their structures are derived from the perovskite one by slicing it with 1/2[110]p(101)p crystallographic shear (CS) planes. The CS operation results in (101)p-shaped perovskite blocks with a thickness of (n – 2) FeO6 octahedra connected to each other through double chains of edge-sharing FeO5 distorted tetragonal pyramids which can adopt two distinct mirror-related configurations. Ordering of chains with a different configuration provides an extra level of structure complexity. Above T ≈ 750 K for Pb2Ba2BiFe5O13 and T ≈ 400 K for Pb1.5Ba2.5Bi2Fe6O16 the chains have a disordered arrangement. On cooling, a second-order structural phase transition to the ordered state oc...
- Published
- 2013
46. Homologous Series of Layered Perovskites An+1BnO3n–1Cl: Crystal and Magnetic Structure of a New Oxychloride Pb4BiFe4O11Cl
- Author
-
Marina G. Rozova, Evgeny V. Antipov, Gustaaf Van Tendeloo, Dmitry Batuk, Maria Batuk, Alexander A. Tsirlin, and Joke Hadermann
- Subjects
Magnetic moment ,Magnetic structure ,Chemistry ,Physics ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Crystallography ,Homologous series ,chemistry.chemical_compound ,Tetragonal crystal system ,Octahedron ,Antiferromagnetism ,Physical and Theoretical Chemistry ,0210 nano-technology ,Superstructure (condensed matter) ,Perovskite (structure) - Abstract
The nuclear and magnetic structure of a novel oxychloride Pb(4)BiFe(4)O(11)Cl has been studied over the temperature range 1.5-700 K using a combination of transmission electron microscopy and synchrotron and neutron powder diffraction [space group P4/mbm, a = 5.5311(1) Å, c = 19.586(1) Å, T = 300 K]. Pb(4)BiFe(4)O(11)Cl is built of truncated (Pb,Bi)(3)Fe(4)O(11) quadruple perovskite blocks separated by CsCl-type (Pb,Bi)(2)Cl slabs. The perovskite blocks consist of two layers of FeO(6) octahedra located between two layers of FeO(5) tetragonal pyramids. The FeO(6) octahedra rotate about the c axis, resulting in a √2a(p) × √2a(p) × c superstructure. Below T(N) = 595(17) K, Pb(4)BiFe(4)O(11)Cl adopts a G-type antiferromagnetic structure with the iron magnetic moments confined to the ab plane. The ordered magnetic moments at 1.5 K are 3.93(3) and 3.62(4) μ(B) on the octahedral and square-pyramidal iron sites, respectively. Pb(4)BiFe(4)O(11)Cl can be considered a member of the perovskite-based A(n+1)B(n)O(3n-1)Cl homologous series (A = Pb/Bi; B = Fe) with n = 4. The formation of a subsequent member of the series with n = 5 is also demonstrated.
- Published
- 2013
47. Layered oxygen vacancy ordering in Nb-doped SrCo1-xFexO3-δperovskite
- Author
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Jo Verbeeck, Stuart Turner, Walid Dachraoui, Haiyan Tan, Olga Yu. Podyacheva, Artem M. Abakumov, Joke Hadermann, and Senne Van Rompaey
- Subjects
Chemistry ,Electron energy loss spectroscopy ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Dark field microscopy ,0104 chemical sciences ,Inorganic Chemistry ,Crystallography ,Tetragonal crystal system ,Electron diffraction ,Scanning transmission electron microscopy ,Precession electron diffraction ,General Materials Science ,0210 nano-technology ,Perovskite (structure) - Abstract
The crystal structure of SrCo 0.7 Fe 0.2 Nb 0.1 O 2.72 was determined using a combination of precession electron diffraction (PED), high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and spatially resolved electron energy loss spectroscopy (STEM-EELS). The structure has a tetragonal P4/mmm symmetry with cell parameters a = b = a p , c = 2a p (a p being the cell parameter of the perovskite parent structure). Octahedral BO 2 layers alternate with the anion-deficient BO 1.4 layers, the different B cations are randomly distributed over both layers. The specific feature of the SrCo 0.7 Fe 0.2 Nb 0.1 O 2.72 microstructure is a presence of extensive nanoscale twinning resulting in domains with alignment of the tetragonal c-axis along all three cubic direction of the perovskite subcell.
- Published
- 2013
48. ChemInform Abstract: Synthesis, Structure and Electrochemical Properties of LiNaCo0.5Fe0.5PO4F Fluoride-Phosphate
- Author
-
Nellie R. Khasanova, Evgeny V. Antipov, D. S. Filimonov, Stanislav S. Fedotov, Artem M. Abakumov, Sergey M. Kuzovchikov, Olesia M. Karakulina, Joke Hadermann, and Oleg A. Drozhzhin
- Subjects
chemistry.chemical_compound ,chemistry ,Inorganic chemistry ,Solid-state ,General Medicine ,Electrochemistry ,Phosphate ,Fluoride ,Stoichiometry - Abstract
The title compound is synthesized by solid state reaction of stoichiometric amounts of LiCo0.5Fe0.5PO4 and NaF (1.
- Published
- 2016
49. Gaining new insight into low-temperature aqueous photochemical solution deposited ferroelectric PbTiO3 films
- Author
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An Hardy, M. Lourdes Calzada, Joke Hadermann, Iñigo Bretos, Jesús Ricote, Christopher De Dobbelaere, Ricardo Jiménez, Marlies K. Van Bael, Ministerio de Economía y Competitividad (España), and Research Foundation - Flanders
- Subjects
Sol-gel growth ,Materials science ,Aqueous solution ,Ferroelectricity ,Physics ,Thin films ,Inorganic chemistry ,Inorganic compounds ,Nanotechnology ,Oxides ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Heat treatment ,0104 chemical sciences ,General Materials Science ,Thin film ,0210 nano-technology - Abstract
The nature of the low-temperature photochemical assisted formation process of ferroelectric lead titanate (PbTiO) films is studied in the present work. Films are obtained by the deposition of an aqueous solution containing citric acid based (citrato) metal ion complexes with intrinsic UV activity. This UV activity is crucial for the aqueous photochemical solution deposition (aqueous PCSD) route being used. UV irradiation enhances the early decomposition of organics and results in improved electrical properties for the crystalline oxide film, even if the film is crystallized at low temperature. GATR-FTIR shows that UV irradiation promotes the decomposition of organic precursor components, resulting in homogeneous films if applied in the right temperature window during film processing. The organic content, morphology and crystallinity of the irradiated films, achieved at different processing atmospheres and temperatures, is studied and eventually correlated to the functional behavior of the obtained films. This is an important issue, as crystalline films obtained at low temperatures often lack ferroelectric responses. In this work, the film prepared in pure oxygen at the very low temperature of 400 °C and after an optimized UV treatment presents a significant remanent polarization value of P = 8.8 μC cm. This value is attributed to the better crystallinity, the larger grain size and the reduced porosity obtained thanks to the early film crystallization effectively achieved through the UV treatment in oxygen., C. De Dobbelaere is a post-doctoral research fellow of the Research Foundation-Flanders (FWO Vlaanderen). Some of this work has been financed by the Spanish Project MAT2013-40489-P.
- Published
- 2016
50. Structural chemistry and magnetic properties of the perovskite <tex>SrLa_{2}Ni_{2}TeO_{9}$</tex>
- Author
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Chun-Mann Chin, Peter D. Battle, Joke Hadermann, Robert Paria Sena, and Emily C. Hunter
- Subjects
Spin glass ,Magnetism ,Neutron diffraction ,02 engineering and technology ,010402 general chemistry ,Perovskite ,01 natural sciences ,Inorganic Chemistry ,Materials Chemistry ,Electron microscopy ,Antiferromagnetism ,Physical and Theoretical Chemistry ,Perovskite (structure) ,Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Crystallography ,Ceramics and Composites ,Crystallite ,0210 nano-technology ,Crystal twinning ,Monoclinic crystal system - Abstract
A polycrystalline sample of SrLa2Ni2TeO9 has been synthesized using a standard ceramic method and characterized by neutron diffraction, magnetometry and electron microscopy. The compound adopts a monoclinic, perovskite-like structure with space group P2(1)/n in and unit cell parameters a=5.6008(1), b = 5.5872(1), c=7.9018(2) angstrom, p=90.021(6)degrees at room temperature. The two crystallographically-distinct B sites are occupied by Ni2+ and Te6+ in ratios of 83:17 and 50:50. Both ac and dc magnetometry suggest that the compound is a spin glass below 35 K but the neutron diffraction data show that some regions of the sample are antiferromagnetic. Electron microscopy revealed twinning on a nanoscale and local variations in composition. These defects are thought to be responsible for the presence of two distinct types of antiferromagnetic ordering. (C) 2016 The Authors. Published by Elsevier Inc.
- Published
- 2016
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