175 results on '"Krystian Roleder"'
Search Results
2. Emergence of high piezoelectricity from competing local polar order-disorder in relaxor ferroelectrics
- Author
-
Hui Liu, Xiaoming Shi, Yonghao Yao, Huajie Luo, Qiang Li, Houbing Huang, He Qi, Yuanpeng Zhang, Yang Ren, Shelly D. Kelly, Krystian Roleder, Joerg C. Neuefeind, Long-Qing Chen, Xianran Xing, and Jun Chen
- Subjects
Science - Abstract
Understanding high piezoelectricity in relaxors is challenging due to the heterogeneous structures. Here, the authors demonstrate that the competing local polar order-disorder state with balanced length and direction randomness is the key.
- Published
- 2023
- Full Text
- View/download PDF
3. SrTiO3: Thoroughly Investigated but Still Good for Surprises
- Author
-
Annette Bussmann-Holder, Reinhard K. Kremer, Krystian Roleder, and Ekhard K. H. Salje
- Subjects
perovskites ,strontium titanate ,phase transitions ,Physics ,QC1-999 - Abstract
For decades, SrTiO3 has been in the focus of research with seemingly never-ending new insights regarding its ground state properties, application potentials, its surface and interface properties, the superconducting state, the twin boundaries, domain functionalities, etc. Here, we focus on the already well-investigated lattice dynamics of STO and show that four different temperature regimes can be identified which dominate the elastic properties, the thermal conductivity, and the birefringence. These regimes are a low-temperature quantum fluctuation-dominated one, followed by an intermediate regime, a region of structural phase transition at ~105 K and its vicinity, and at high temperatures, a regime characterized by precursor and saturation effects. They can all be elucidated by lattice dynamical aspects. The relevant temperature dependences of the soft modes are discussed and their relationship to lattice polarizability is emphasized.
- Published
- 2024
- Full Text
- View/download PDF
4. Intriguing spin–lattice interactions in EuTiO3
- Author
-
Annette Bussmann-Holder, Efthymios Liarokapis, and Krystian Roleder
- Subjects
Medicine ,Science - Abstract
Abstract During the last decade the cubic perovskite oxide EuTiO3 (ETO) has attracted enormous novel research activities due to possible multiferroicity, hidden magnetism far above its Néel temperature at TN = 5.5 K, structural instability at TS = 282 K, possible application as magneto-electric optic device, and strong spin–lattice coupling. Here we address a novel highlight of this compound by showing that well below TS a further structural phase transition occurs below 210 K without the application of an external magnetic field, and by questioning the assumed tetragonal symmetry of the structure below TS where tiny deviations from true tetragonality are observed by birefringence and XRD measurements. It is suggested that the competition in the second nearest neighbor spin–spin interaction modulated by the lattice dynamics is at the origin of these new observations.
- Published
- 2021
- Full Text
- View/download PDF
5. Influence of Defects-Induced Stresses on Birefringence in SrTiO3 Single Crystals
- Author
-
Iwona Lazar, Krzysztof Szot, and Krystian Roleder
- Subjects
strontium titanate ,birefringence ,extended defects ,bi-crystal ,Crystallography ,QD901-999 - Abstract
Significant applications of SrTiO3 single crystals in electronics require knowledge about the influence of structural imperfections on their optical properties. Birefringence temperature changes were investigated in a few SrTiO3 single crystals in a broad temperature range, from 85 K to 250 K. The birefringence was found to be a non-linear function below the transition Ts at 105 K, and non-linear changes in the optical indicatrix orientation accompanied it. A weak residual birefringence was permanently present a dozen degrees above the phase transition temperature Ts. This is mainly connected with dislocations, which induce local stresses and shift transition points even up to about 200 K. The essential role of imperfections on optical properties was studied in a SrTiO3 24° bi-crystal reduced at 1000 K and under low oxygen pressure. In such an intentionally defected crystal, an increase of non-linearities in Δn(T) dependence was observed below and above the transition point Ts.
- Published
- 2023
- Full Text
- View/download PDF
6. First experimental evidence of the piezoelectric nature of struvite
- Author
-
Jolanta Prywer, Rafał Kruszyński, Marcin Świątkowski, Andrzej Soszyński, Dariusz Kajewski, and Krystian Roleder
- Subjects
Medicine ,Science - Abstract
Abstract In this paper, we present the first experimental evidence of the piezoelectric nature of struvite (MgNH4PO4·6H2O). Using a single diffusion gel growth technique, we have grown struvite crystals in the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric coefficients d 33 and d 32. We have found that at room temperature the value of piezoelectric coefficient d 33 is 3.5 pm/V, while that of d 32 is 4.7 pm/V. These values are comparable with the values for other minerals. Struvite shows stable piezoelectric properties up to the temperature slightly above 350 K, for the heating rate of 0.4 K/min. For this heating rate, and above this temperature, the thermal decomposition of struvite begins, which, consequently, leads to its transformation into dittmarite with the same non-centrosymmetric symmetry as in case of struvite. The struvite-dittmarite transformation temperature is dependent on the heating rate. The higher the heating rate, the higher the temperature of this transformation. We have also shown that dittmarite, like struvite exhibits piezoelectric properties.
- Published
- 2021
- Full Text
- View/download PDF
7. The Electrodegradation Process in PZT Ceramics under Exposure to Cosmic Environmental Conditions
- Author
-
Iwona Lazar, Christian Rodenbücher, Gustav Bihlmayer, Clive A. Randall, Janusz Koperski, Lutz Nielen, Krystian Roleder, and Krzysztof Szot
- Subjects
PZT ceramics ,electrodegradation ,oxygen vacancies ,oxygen effusion ,grain boundaries ,dislocations ,Organic chemistry ,QD241-441 - Abstract
Long-time electric field action on perovskite piezoelectric ceramic leads to chemical degradation. A new way to accelerate the degradation is the exposure of the ceramic to DC electric fields under a vacuum. A high-quality commercial piezoelectric material based on PbZr1−xTixO3 is used to study such impacts. To avoid the influence of ferroelectric properties and possible removal of oxygen and lead oxides during the degradation process, the experiments are in the temperature interval of 500 °C > T > TC. Changes in resistance during the electrodegradation process is an electrically-induced deoxidation, transforming the ceramic into a metallic-like material. This occurs with an extremely low concentration of effused oxygen of 1016 oxygen atoms per 1 cm3. Due to this concentration not obeying the Mott criterion for an isolator-metal transition, it is stated that the removal of oxygen mostly occurs along the grain boundaries. It agrees with the first-principle calculations regarding dislocations with oxygen vacancies. The decrease in resistivity during electrodegradation follows a power law and is associated with a decrease in the dislocation dimension. The observed reoxidation process is a lifeline for the reconstructing (self-healing) properties of electro-degraded ceramics in harsh cosmic conditions. Based on all of these investigations, a macroscopic and nanoscopic model of the electrodegradation is presented.
- Published
- 2023
- Full Text
- View/download PDF
8. Ultrahigh Piezoelectric Strains in PbZr1−xTixO3 Single Crystals with Controlled Ti Content Close to the Tricritical Point
- Author
-
Iwona Lazar, Roger William Whatmore, Andrzej Majchrowski, Anthony Mike Glazer, Dariusz Kajewski, Janusz Koperski, Andrzej Soszyński, Julita Piecha, Barbara Loska, and Krystian Roleder
- Subjects
ABO3 perovskites ,ferroelectric and antiferroelectric phase transitions ,PZT single crystals ,piezoelectricity ,tricritical point ,birefringence ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Intensive investigations of PbZr1-xTixO3 (PZT) materials with the ABO3 perovskite structure are connected with their extraordinary piezoelectric properties. Especially well known are PZT ceramics at the Morphotropic Phase Boundary (MPB), with x~0.48, whose applications are the most numerous among ferroelectrics. These piezoelectric properties are often obtained by doping with various ions at the B sites. Interestingly, we have found similar properties for undoped PZT single crystals with low Ti content, for which we have confirmed the existence of the tricritical point near x~0.06. For a PbZr0.95 ± 0.01Ti0.05∓ 0.01O3 crystal, we describe the ultrahigh strain, dielectric, optical and piezoelectric properties. We interpret the ultrahigh strain observed in the region of the antiferroelectric–ferroelectric transition as an inverse piezoelectric effect generated by the coexistence of domains of different symmetries. The complex domain coexistence was confirmed by determining optical indicatrix orientations in domains. The piezoelectric coefficient in this region reached an extremely high value of 5000 pm/V. We also verified that the properties of the PZT single crystals from the region near the tricritical point are incredibly susceptible to a slight deviation in the Ti content.
- Published
- 2022
- Full Text
- View/download PDF
9. Long-Term Isothermal Phase Transformation in Lead Zirconate
- Author
-
Dariusz Kajewski, Irena Jankowska-Sumara, Jae-Hyeon Ko, Jeong Woo Lee, Syed Furqan Ul Hassan Naqvi, Rafał Sitko, Andrzej Majchrowski, and Krystian Roleder
- Subjects
lead zirconate ,phase transition ,Raman scattering ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Lead zirconate PbZrO3 has been the subject of research interest for several dozen years. Recently, even its antiferroelectric properties have started to be questioned, and many researchers still deal with the so-called intermediate phase below Curie temperature (TC), whose existence is not fully understood. It turns out that PbZrO3 doped with Nb exhibits below TC phases with complex domain structures. One of them undergoes self-organization taking place at a constant temperature, and transforms, after several minutes, into a lower phase. This isothermal transition was investigated through dielectric, pyroelectric current and Raman scattering measurements. Discontinuities accompanied it in the permittivity and pyroelectric current. The obtained Raman spectra proved that those discontinuities are strictly linked with the isothermal transition between two intermediate phases. The ordering process in lead sublattice stimulated by thermal fluctuations is discussed as a driving force for this peculiar phenomenon.
- Published
- 2022
- Full Text
- View/download PDF
10. Author Correction: Intriguing spin–lattice interactions in EuTiO3
- Author
-
Annette Bussmann‑Holder, Efthymios Liarokapis, and Krystian Roleder
- Subjects
Medicine ,Science - Published
- 2022
- Full Text
- View/download PDF
11. Unconventional Co-Existence of Insulating Nano-Regions and Conducting Filaments in Reduced SrTiO3: Mode Softening, Local Piezoelectricity, and Metallicity
- Author
-
Annette Bussmann-Holder, Hugo Keller, Arndt Simon, Gustav Bihlmayer, Krystian Roleder, and Krzysztof Szot
- Subjects
SrTiO3 ,metal – insulator transition ,lattice dynamics ,Crystallography ,QD901-999 - Abstract
Doped SrTiO3 becomes a metal at extremely low doping concentrations n and is even superconducting at n < 1020 cm−3, with the superconducting transition temperature adopting a dome-like shape with increasing carrier concentration. In this paper it is shown within the polarizability model and from first principles calculations that up to a well-defined carrier concentration nc transverse optic mode softening takes place together with polar nano-domain formation, which provides evidence of inhomogeneity and a two-component type behavior with metallicity coexisting with polarity. Beyond this region, a conventional metal is formed where superconductivity as well as mode softening is absent. For n ≤ nc the effective electron-phonon coupling follows the superconducting transition temperature. Effusion measurements, as well as macroscopic and nanoscopic conductivity measurements, indicate that the distribution of oxygen vacancies is local and inhomogeneous, from which it is concluded that metallicity stems from filaments which are embedded in a polar matrix as long as n ≤ nc.
- Published
- 2020
- Full Text
- View/download PDF
12. Phase Transitions and Local Polarity above TC in a PbZr0.87Ti0.13O3 Single Crystal
- Author
-
Iwona Lazar, Andrzej Majchrowski, Andrzej Soszyński, and Krystian Roleder
- Subjects
PZT single crystal ,birefringence ,dielectric and pyroelectric properties ,elasticity ,phase transitions ,local polarity ,Crystallography ,QD901-999 - Abstract
Solid solutions of PbZr1−xTixO3 (PZT) are one of the most widely used piezoelectric materials with perovskite structure. Despite the decades of research, the phase diagram of PZT reported in 1971 has not been resolved yet. Recently, it turned out that single crystals of good quality of these solid solutions can be grown. By means of top-seeded solution growth (TSSG) technique, we succeeded to grow a single PbZr0.87Ti0.13O3 crystal. Hence, a partial verification of the diagram could be performed through investigations of the optical, dielectric, pyroelectric and elastic properties of this crystal, in a wide temperature range. The obtained results confirmed that the PbZr0.87Ti0.13O3 crystal undergoes a sequence of phase transitions, such as those observed in ceramics of similar chemical composition. However, additional anomalies of investigated physical properties were observed and discussed. Moreover, the influence of electric field on optical properties has been investigated for the first time and has proven the existence of local polar character of the phase above TC in a limited temperature range.
- Published
- 2020
- Full Text
- View/download PDF
13. Precursor Phenomena of Barium Titanate Single Crystals Grown Using a Solid-State Single Crystal Growth Method Studied with Inelastic Brillouin Light Scattering and Birefringence Measurements
- Author
-
Soo Han Oh, Jae-Hyeon Ko, Ho-Yong Lee, Iwona Lazar, and Krystian Roleder
- Subjects
barium titanate ,BaTiO3 ,Brillouin spectroscopy ,acoustic property ,precursor phenomena ,Organic chemistry ,QD241-441 - Abstract
The nature of precursor phenomena in the paraelectric phase of ferroelectrics is one of the main questions to be resolved from a fundamental point of view. Barium titanate (BaTiO3) is one of the most representative perovskite-structured ferroelectrics intensively studied until now. The pretransitional behavior of BaTiO3 single crystal grown using a solid-state crystal growth (SSCG) method was investigated for the first time and compared to previous results. There is no melting process in the SSCG method, thus the crystal grown using a SSCG method have inherent higher levels of impurity and defect concentrations, which is a good candidate for investigating the effect of crystal quality on the precursor phenomena. The acoustic, dielectric, and piezoelectric properties, as well as birefringence, of the SSCG-grown BaTiO3 were examined over a wide temperature range. Especially, the acoustic phonon behavior was investigated in terms of Brillouin spectroscopy, which is a complementary technique to Raman spectroscopy. The obtained precursor anomalies of the SSCG-grown BaTiO3 in the cubic phase were similar to those of other single crystals, in particular, of high-quality single crystal grown by top-seeded solution growth method. These results clearly indicate that the observed precursor phenomena are common and intrinsic effect irrespective of the crystal quality.
- Published
- 2018
- Full Text
- View/download PDF
14. Influence of KF substitution on the ferroelectric phase transition of lead titanate single crystals studied by Brillouin light scattering
- Author
-
Seonhyeop Shin, Jae-Hyeon Ko, Shinya Tsukada, Yukikuni Akishige, Krystian Roleder, and Daniel Rytz
- Subjects
Lead titanate ,KF-substitution ,elastic property ,Brillouin scattering ,Electricity ,QC501-721 - Abstract
The elastic properties of KF-substituted perovskite lead titanate (PbTiO3) were investigated by dielectric measurements and Brillouin light scattering. The ferroelectric phase transition occurred at substantially lower temperature due to KF substitution, which was attributed to the modification of the covalency in Pb–O and Ti–O bonds. The longitudinal acoustic (LA) mode of KF-substituted PbTiO3 showed a frequency softening in the paraelectric phase, which was accompanied by increasing acoustic damping. This indicated that polarization fluctuations responsible for the acoustic anomalies were enhanced by KF substitution.
- Published
- 2015
- Full Text
- View/download PDF
15. Monoclinic domain populations and enhancement of piezoelectric properties in a PZT single crystal at the morphotropic phase boundary
- Author
-
Krystian Roleder, Andrzej Majchrowski, Iwona Lazar, Roger W. Whatmore, A. Mike Glazer, Dariusz Kajewski, Janusz Koperski, and Andrzej Soszyński
- Subjects
TA ,QD ,QC - Abstract
The origin of the strong piezoelectric phenomenon in PbZr1−xTixO3 (PZT) perovskites still suffers from a lack of complete understanding. It concerns the distinction between the intrinsic and extrinsic mechanisms that govern PZT's piezo activity. These two mechanisms have been investigated in single crystal PbZr0.54Ti0.46O3 at the morphotropic phase boundary. After poling in a DC electric field, the piezoelectric properties were examined on the same crystal by observing piezoelectric resonances to determine the piezoelectric coefficient d31 and measuring quasistatic deformation to determine the coefficient d33. The domain populations were investigated during and after poling in a DC electric field. These populations were also investigated as a function of DC fields for strengths similar to those used to measure quasistatic piezoelectric properties for a poled crystal. The experiments indicate that the intrinsic origin of the enhancement of the piezoelectric properties is connected with a change in the population of domains with monoclinic symmetry, in which there is an easy polarization rotation under the action of the electric field.
- Published
- 2022
16. First Experimental Evidences of the Ferroelectric Nature of Struvite
- Author
-
Jolanta Prywer, Andrzej Soszyński, F. Cugini, A. Ciżman, Krystian Roleder, Massimo Solzi, Davide Delmonte, and Jan K. Zaręba
- Subjects
Ferroelectrics ,Minerals ,Nonlinear optics ,Mineral ,Materials science ,010405 organic chemistry ,General Chemistry ,010402 general chemistry ,Condensed Matter Physics ,Crystals ,01 natural sciences ,Ferroelectricity ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Struvite ,Polarization ,General Materials Science ,Anatomy ,Polarization (electrochemistry) - Abstract
Struvite (MgNH4PO4·6H2O) is a mineral first identified in 1845. It is tested for several reasons: (1) it is a problem in liquid wastewater treatment plants; (2) on the other hand, it is recovered from this wastewater because of phosphorus, magnesium, and nitrogen; (3) it is the main component of infectious urinary stones. In this paper, we present the first experimental evidences of the ferroelectric nature of struvite at room temperature. Struvite shows a hysteresis loop and spontaneous electric polarization that can be reversed by an application of an external electric field. The measured value of residual polarization of struvite is equal to 0.95 μC/cm2. We also report observations of the ferroelectric domains in struvite using birefringence imaging technique. The non-centrosymmetry of the crystal lattice is confirmed with the use of the Kurtz−Perry powder test. The second harmonic generation response for struvite in relation to that of potassium dihydrogen phosphate is 0.36. We suggest that ferroelectric properties for struvite, in particular, spontaneous polarization, can have a significant impact on the behavior of struvite in aqueous solutions, such as liquid wastewater or urine.
- Published
- 2020
17. Influence of Nb 5+ ions on phase transitions and polar disorder above T C in PbZrO 3 studied by Raman spectroscopy
- Author
-
Dariusz Kajewski, Andrzej Majchrowski, Rafal Sitko, Krystian Roleder, Irena Jankowska-Sumara, Jae-Hyeon Ko, Annette Bussmann-Holder, and Jeong Woo Lee
- Subjects
Phase transition ,Crystallography ,symbols.namesake ,Materials science ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Niobium ,symbols ,chemistry.chemical_element ,Polar ,Raman spectroscopy ,Ion - Published
- 2020
18. Incommensurate crystal structure of PbHfO3
- Author
-
Alexei Bosak, Volodymyr Svitlyk, Alla Arakcheeva, Vadim Diadkin, R. G. Burkovsky, Dmitry Chernyshov, and Krystian Roleder
- Subjects
010302 applied physics ,Diffraction ,Phase transition ,Chemistry ,Parent structure ,Metals and Alloys ,02 engineering and technology ,Crystal structure ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Crystal ,Crystallography ,Octahedron ,Phase (matter) ,0103 physical sciences ,Materials Chemistry ,Antiferroelectricity ,0210 nano-technology - Abstract
Controversy in the description/identification of so-called intermediate phase(s) in PbHfO3, stable in the range ∼420–480 K, has existed for a few decades. A synchrotron diffraction experiment on a partially detwinned crystal allowed the structure to be solved in the superspace groupImma(00γ)s00 (No. 74.2). In contrast to some previously published reports, in the pure compound only one distinct phase was observed betweenPbamPbZrO3-like antiferroelectric andPm3mparaelectric phases. The modulation vector depends only slightly on temperature. The major structure modulation is associated with the displacement of lead ions, which is accompanied by a smaller amplitude modulation for the surrounding O atoms and tilting of HfO6octahedra. Tilting of the octahedra results in a doubling of the unit cell compared with the parent structure.
- Published
- 2020
19. Ferroelectric to incommensurate fluctuations crossover in PbHfO3−PbSnO3
- Author
-
Maria A. Kniazeva, Alexander E. Ganzha, Irena Jankowska-Sumara, Marek Paściak, Andrzej Majchrowski, Alexey V. Filimonov, Andrey I. Rudskoy, Krystian Roleder, and Roman G. Burkovsky
- Published
- 2022
20. Translational boundaries as incipient ferrielectric domains in antiferroelectric PbZrO3
- Author
-
Ying Liu, Ranming Niu, Andrzej Majchrowski, Krystian Roleder, Kumara Cordero-Edwards, Julie M. Cairney, Jordi Arbiol, and Gustau Catalan
- Subjects
Condensed Matter - Materials Science ,General Physics and Astronomy ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences - Abstract
In the archetypal antiferroelectric PbZrO3, antiparallel electric dipoles cancel each other, resulting in zero spontaneous polarisation at the macroscopic level. Yet in actual hysteresis loops, the cancellation is rarely perfect and some remnant polarization is often observed, suggesting the metastability of polar phases in this material. In this work, using aberration-corrected scanning transmission electron microscopy methods on a PbZrO3 single crystal, we uncover the coexistence of the common antiferroelectric phase and a ferrielectric phase featuring an electric dipole pattern of "up down up". This dipole arrangement, predicted by Aramberri et al. (2021) to be the ground state of PbZrO3 at 0K, appears at room temperature in the form of translational boundaries that aggregate to form wider stripe domains of the polar phase embedded within the antiferroelectric matrix.
- Published
- 2022
- Full Text
- View/download PDF
21. Correlating hidden local structural distortion with antiferroelectric-ferroelectric transition in PbZrO3-based perovskites
- Author
-
Hui Liu, Zheng Sun, Ling Li, Baotao Gao, Yueyun Zhang, He Qi, Kenichi Kato, Krystian Roleder, Yang Ren, and Jun Chen
- Subjects
Polymers and Plastics ,Metals and Alloys ,Ceramics and Composites ,Electronic, Optical and Magnetic Materials - Published
- 2023
22. First experimental evidence of the piezoelectric nature of struvite
- Author
-
Marcin Świątkowski, Krystian Roleder, Dariusz Kajewski, Jolanta Prywer, Rafal Kruszynski, and Andrzej Soszyński
- Subjects
Piezoelectric coefficient ,Materials science ,Science ,Diffusion ,Thermodynamics ,Struvite Crystals ,010501 environmental sciences ,01 natural sciences ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Condensed-matter physics ,030304 developmental biology ,0105 earth and related environmental sciences ,0303 health sciences ,Plane parallel ,Multidisciplinary ,Thermal decomposition ,Piezoelectricity ,chemistry ,Struvite ,Medicine ,Dittmarite - Abstract
In this paper, we present the first experimental evidence of the piezoelectric nature of struvite (MgNH4PO4·6H2O). Using a single diffusion gel growth technique, we have grown struvite crystals in the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric coefficients d33 and d32. We have found that at room temperature the value of piezoelectric coefficient d33 is 3.5 pm/V, while that of d32 is 4.7 pm/V. These values are comparable with the values for other minerals. Struvite shows stable piezoelectric properties up to the temperature slightly above 350 K, for the heating rate of 0.4 K/min. For this heating rate, and above this temperature, the thermal decomposition of struvite begins, which, consequently, leads to its transformation into dittmarite with the same non-centrosymmetric symmetry as in case of struvite. The struvite-dittmarite transformation temperature is dependent on the heating rate. The higher the heating rate, the higher the temperature of this transformation. We have also shown that dittmarite, like struvite exhibits piezoelectric properties.
- Published
- 2021
23. Phase Transitions in Lead Hafnate under High Pressure
- Author
-
P. Paraskevas, Krystian Roleder, Daria Andronikova, I. A. Bronwald, G. A. Lityagin, R. G. Burkovsky, A. Majchrowski, M. A. Knyazeva, and A. V. Filimonov
- Subjects
010302 applied physics ,Diffraction ,Phase transition ,Materials science ,Hydrostatic pressure ,Condensation ,Analytical chemistry ,Soft modes ,Atmospheric temperature range ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Phase (matter) ,0103 physical sciences ,Antiferroelectricity ,010306 general physics - Abstract
The effect of hydrostatic pressure on phase transitions in lead hafnate (PbHfO3) has been studied by the methods of X-ray diffraction and X-ray diffuse scattering. The measurements were performed in the temperature range of 182 < T < 316°C and the pressure range of 1.6 < P < 2.6 GPa. Four regions characterized by different X-ray diffraction patterns and corresponding to an antiferroelectric phase, phases with a long-wavelength modulation of the lead sublattice, and phases with different distortions of the oxygen sublattice are identified. In the temperature region immediately above the region of phases with a long-wavelength modulation, a temperature-dependent maximum in the distribution of diffuse scattering was detected, which means that such a modulation is formed due to condensation of an incommensurate soft mode.
- Published
- 2019
24. Paraelectric Elastic Properties of Reduced and Heterovalently Doped BaTiO3 Single Crystals Studied by Using Brillouin Spectroscopy
- Author
-
Jae-Hyeon Ko, Jeong Woo Lee, Krystian Roleder, and D. Rytz
- Subjects
010302 applied physics ,Phase transition ,Brillouin Spectroscopy ,Birefringence ,Materials science ,Condensed matter physics ,Doping ,General Physics and Astronomy ,02 engineering and technology ,Dielectric ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,01 natural sciences ,Condensed Matter::Materials Science ,Condensed Matter::Superconductivity ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,Charge carrier ,0210 nano-technology ,Softening - Abstract
The effects of rhodium (Rh) doping on the elastic properties and phase transition behaviors of reduced BaTiO3 single crystals were investigated in the paraelectric phase by using Brillouin spectroscopy. The Rh doping induced changes in the elastic stiffness coefficients and the elastic anisotropy parameter. The degree of softening of (C11 − C12)/2 became more substantial with Rh doping, indicating that the polarization fluctuations were enhanced by heterovalent Rh3+ doping. This was supported by the much larger temperature range over which the nonzero birefringence was observed. Free charge carriers introduced by Rh doping and oxygen vacancies in the reduced BaTiO3 and their interactions with the lattice seem to be the origin of these anomalous changes in the elastic properties.
- Published
- 2019
25. Elastic Anisotropy and Slowness Curves of BaTiO3 Single Crystals in the Paraelectric Phase Studied by Brillouin Spectroscopy
- Author
-
Krystian Roleder, D. Rytz, Jae-Hyeon Ko, and Jeong Woo Lee
- Subjects
010302 applied physics ,Brillouin Spectroscopy ,Materials science ,Condensed matter physics ,Transition temperature ,General Physics and Astronomy ,02 engineering and technology ,Acoustic wave ,021001 nanoscience & nanotechnology ,01 natural sciences ,Condensed Matter::Materials Science ,Transverse plane ,chemistry.chemical_compound ,Tetragonal crystal system ,chemistry ,Brillouin scattering ,Phase (matter) ,0103 physical sciences ,Barium titanate ,0210 nano-technology - Abstract
Elastic anisotropy and slowness curves of barium titanate (BaTiO3) single crystal in the paraelectric phase were investigated by using Brillouin spectroscopy. The directional dependence of sound velocities of the longitudinal and the transverse acoustic waves in the (001) plane showed a four-fold symmetry typical in the cubic phase. Especially, one of the two transverse modes exhibited a substantial softening along the directions. The sound velocity of this mode decreased significantly as temperature decreased toward the transition temperature, which corresponded to the elastic stiffness coefficient (C11 – C12)/2. This result suggests the tetragonal instability caused by the precursor polar clusters in the paraelectric phase of BaTiO3.
- Published
- 2019
26. Bismuth doped PbZr0.70Ti0.30O3 ceramics and their properties driven by high temperature local polarity
- Author
-
Iwona Lazar, Dariusz Kajewski, Krystian Roleder, Paweł Zajdel, Andrzej Soszyński, and Janusz Koperski
- Subjects
Permittivity ,Phase transition ,Materials science ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,Dielectric ,01 natural sciences ,Bismuth ,chemistry.chemical_compound ,0103 physical sciences ,Materials Chemistry ,Ceramic ,010302 applied physics ,Condensed matter physics ,Dopant ,Process Chemistry and Technology ,Doping ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,visual_art ,Ceramics and Composites ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
Lead zirconate-titanate PbZr0.70Ti0.30O3 ceramics doped with bismuth oxide has been investigated. Dielectric and optical measurements were performed to check the dopant influence on phase transitions and pre-transitional effects. It has been postulated that the temperature at which maximum permittivity occurs is not connected with structural phase transitions.
- Published
- 2019
27. Weak ferromagnetic response in PbZr1−xTixO3 single crystals
- Author
-
Krystian Roleder, Iwona Lazar, Jerzy Kubacki, Andrzej Majchrowski, M. Oboz, Dariusz Kajewski, and Julita Piecha
- Subjects
Materials science ,Condensed matter physics ,Ferromagnetic material properties ,Dopant ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Ferroelectricity ,Piezoelectricity ,0104 chemical sciences ,Condensed Matter::Materials Science ,Ferromagnetism ,chemistry ,Oxidation state ,Condensed Matter::Superconductivity ,Physics::Atomic and Molecular Clusters ,Materials Chemistry ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology ,Titanium ,Perovskite (structure) - Abstract
For the first time, a weak ferromagnetic hysteresis loop at room temperature has been observed in PbZr1−xTixO3 (PZT) single crystals. The occurrence of these properties has been related to the presence of oxygen vacancies and/or lower oxidation state of titanium. This proves that ferroelectric and ferromagnetic properties can occur simultaneously in this “famous” piezoelectric perovskite without any magnetic dopant.
- Published
- 2019
28. Direct Visualization of Anti-Ferroelectric Switching Dynamics via Electrocaloric Imaging
- Author
-
Miquel Vellvehi, Gustau Catalan, Xavier Jordà, Xavier Perpiñà, Krystian Roleder, Emmanuel Defay, Pablo Vales-Castro, Dariusz Kajewski, Amador Pérez-Tomás, Romain Faye, Jose Manuel Caicedo, Generalitat de Catalunya, Ministerio de Economía, Industria y Competitividad (España), Fonds National de la Recherche Luxembourg, National Science Centre (Poland), Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), and Ministerio de Ciencia, Innovación y Universidades (España)
- Subjects
Condensed Matter - Materials Science ,Phase boundary ,Materials science ,business.industry ,Dynamics (mechanics) ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,phase boundary ,Ferroelectricity ,electrocalorics ,Electronic, Optical and Magnetic Materials ,Visualization ,Optoelectronics ,infrared thermometry ,anti-ferroelectrics ,Infrared thermometry ,business - Abstract
The large electrocaloric coupling in PbZrO3 allows using high-speed infrared imaging for visualizing anti-ferroelectric switching dynamics via the associated temperature change. It is found that in ceramic samples of homogeneous temperature and thickness, switching is fast due to the generation of multiple nucleation sites, with devices responding in the millisecond range. By introducing gradients of thickness, however, it is possible to change the dynamics to propagation limited, whereby a single-phase boundary sweeps across the sample like a cold front, at a speed of ≈20 cm s−1. Additionally, introducing thermostatic temperature differences between two sides of the sample enables the simultaneous generation of a negative electrocaloric effect on one side and a positive one on the other, yielding a Janus-like electrocaloric response., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (SEV-2017-0706)
- Published
- 2021
29. [Methylhydrazinium]2PbBr4, a ferroelectric hybrid organic-inorganic perovskite with multiple nonlinear optical outputs
- Author
-
Anna Gągor, Jan K. Zaręba, Katarzyna Fedoruk, Mirosław Mączka, Krystian Roleder, Maciej Ptak, Andrzej Soszyński, Dagmara Stefańska, Dariusz Kajewski, and Adam Sieradzki
- Subjects
Materials science ,General Chemical Engineering ,Halide ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Ferroelectricity ,0104 chemical sciences ,lead bromide ,Nonlinear optical ,Chemical engineering ,Organic inorganic ,Materials Chemistry ,0210 nano-technology ,Expansive ,perovskite ,Perovskite (structure) - Abstract
An expansive library of structurally complex two-dimensional (2D) and three-dimensional (3D) lead halide perov-skites has emerged over the past decade, finding applications in various aspects of photon management: photovoltaics, photo-detection, light emission, and nonlinear optics. Needless to say, the highest degree of structural plasticity enjoys the former group, offering a rich playground for modifications of relevant optoelec-tronic parameters such as exciton energy. Structural tailorability is reflected in the ease of modification of the chemistry of the organic layers residing between inorganic slabs. In this vein, we show that the introduction of methylhydrazinium cation (MHy+, CH3NH2NH2+) into 2D perovskite gives a material with a record low separation of the inorganic layers (8.91 Å at 300 K). Optical studies showed that MHy2PbBr4 features the most red-shifted excitonic absorption among all known A2PbBr4 compounds as well as a small exciton binding energy of 99.9 meV. MHy2PbBr4 crystallizes in polar Pmn21 symmetry at room emperature (phase III) and at 351 K undergoes a phase transition to modulated Pmnm phase (II) followed by another phase transition at 371 K to Pmnm phase (I). The ferroelectric property of room-temperature phase III is inferred from switching of the pyrocurrent, dielectric measurements, and optical birefringence results. MHy2PbBr4 exhibits multiple nonlinear optical phenomena such as second-harmonic generation, third-harmonic generation, two-photon excited luminescence, and multiphoton excited luminescence. Analysis of MHy2PbBr4 single-crystal luminescence spectra obtained through linear and nonlinear optical excitation pathways indicates that free exciton emission is readily probed by the ultraviolet excitation, whereas crumpled exciton emission is detected under two- and multiphoton excitation conditions. Overall, our results demonstrate that incorporation of MHy+ into the organic layer is an emergent strategy for obtaining a 2D perovskite with polar character and multifunctional properties.
- Published
- 2021
30. Origin of large negative electrocaloric effect in antiferroelectric PbZr O3
- Author
-
Krystian Roleder, Gustau Catalan, Emmanuel Defay, Xavier Perpiñà, Youri Nouchokgwe, Miquel Vellvehi, J. M. Caicedo, Xavier Jordà, Amador Pérez-Tomás, Romain Faye, Pablo Vales-Castro, Dariusz Kajewski, Generalitat de Catalunya, Ministerio de Economía, Industria y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Fonds National de la Recherche Luxembourg, Consejo Superior de Investigaciones Científicas (España), and National Science Centre (Poland)
- Subjects
Condensed Matter - Materials Science ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,02 engineering and technology ,Public administration ,Electro-caloric effects ,021001 nanoscience & nanotechnology ,01 natural sciences ,Infra-red cameras ,Political science ,Ferroelectric switching ,0103 physical sciences ,Electroheating ,Electromechanical measurements ,Electrocaloric ,Christian ministry ,Anti ferroelectrics ,010306 general physics ,0210 nano-technology ,Paraelectric phase transition - Abstract
We have studied the electrocaloric response of the archetypal antiferroelectric PbZrO3 as a function of voltage and temperature in the vicinity of its antiferroelectric-paraelectric phase transition. Large electrocaloric effects of opposite signs, ranging from an electrocooling of −3.5 K to an electroheating of +5.5K, were directly measured with an infrared camera. We show by calorimetric and electromechanical measurements that the large negative electrocaloric effect comes from an endothermic antiferroelectric-ferroelectric switching, in contrast to dipole destabilization of the antiparallel lattice, previously proposed as an explanation for the negative electrocaloric effect of antiferroelectrics., We acknowledge financial support to ICN2, which is funded by the CERCA programme/Generalitat de Catalunya and by the Severo Ochoa programme of the Spanish Ministry of Economy, Industry and Competitiveness (MINECO, Grant No. SEV-2017-0706). We also acknowledge support to Plan Nacional (MINECO Grant No. MAT2016-77100-C2-1-P) and MINECO Grant No. BES-2016-077392. R.F., Y.N., and E.D acknowledge the Luxembourg National Research Fund (FNR) for funding part of this research through the Projects No. CAMELHEAT/C17/MS/11703691/Defay and No. COFERMAT/P12/4853155/Kreisel. This work was also supported in part by the Spanish Ministry of Science, Innovation and Universities under the HIPERCELLS Project No. RTI2018-098392-B-I00, the Regional Government of the Generalitat de Catalunya under Grants No. 2017 SGR 1384 and No. 217 SGR 1384, the Consejo Superior de Investigaciones Científicas through internal research programs with Identification No. 201850I063 and No. 201950E036. This work was also supported by the National Science Centre, Poland, within the Project No. 2016/21/B/ST3/02242.
- Published
- 2021
31. In Situ Observation of Point-Defect-Induced Unit-Cell-WiseEnergy Storage Pathway in Antiferroelectric PbZrO3
- Author
-
Rafal E. Dunin-Borkowski, Chun-Lin Jia, Xian-Kui Wei, Krystian Roleder, and Joachim Mayer
- Subjects
In situ ,Materials science ,energy storage ,Condensed Matter Physics ,Molecular physics ,Energy storage ,Electronic, Optical and Magnetic Materials ,Biomaterials ,In situ transmission electron microscopy ,Electrochemistry ,Antiferroelectricity ,ddc:530 ,Point (geometry) ,PbZrO3 ,in situ transmission electron microscopy ,charged domain walls ,ferrodistortive transition - Abstract
Phase transition is established to govern electrostatic energy storage for antiferroelectric (AFE)‐type dielectric capacitors. However, the source of inducing the phase transition and the pathway of storing the energy remains elusive so far given the ultrafast charging/discharging process under normal working conditions. Here, by slowing down the phase‐transition speed using electron‐beam irradiation as an external stimulus, the in situ dynamic energy‐storage process in AFE PbZrO3 is captured by using atomic‐resolution transmission electron microscopy. Specifically, it is found that oxygen‐lead‐vacancy‐induced defect core acts as a seed to initiate the antiferrodistortive‐to‐ferrodistortive transition in antiparallel‐Pb‐based structural frames. Associated with polarity evolution of the compressively strained defect core, the ferroelectric (FE)–ferrodistortive state expands bilaterally along the b‐axis direction and then develops into charged domain configurations during the energy‐storage process, which is further evidenced by observations at the ordinary FE states. With filling the gap of perception, the findings here provide a straightforward approach of unveiling the unit‐cell‐wise energy storage pathway in chemical defect‐engineered dielectric ceramics.
- Published
- 2021
32. Complex structure and Mössbauer effect observed in the course of phase transitions in PbZr
- Author
-
Irena, Jankowska-Sumara, Mariola, Kądziołka-Gaweł, Maria, Podgórna, Andrzej, Majchrowski, and Krystian, Roleder
- Abstract
The Mössbauer effect was used to study the structural transitions in a PbZr
- Published
- 2020
33. An Unconventional Transient Phase with Cycloidal Order of Polarization in Energy‐Storage Antiferroelectric PbZrO3
- Author
-
Joachim Mayer, Krystian Roleder, Xian-Kui Wei, Rafal E. Dunin-Borkowski, Chun-Lin Jia, and Hongchu Du
- Subjects
Phase transition ,Materials science ,Phase (waves) ,02 engineering and technology ,Dielectric ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Energy storage ,law.invention ,cycloidal polarization ,Condensed Matter::Materials Science ,law ,Antiferroelectricity ,General Materials Science ,ferrodistortive phase ,PbZrO3 ,Condensed matter physics ,energy storage ,Mechanical Engineering ,021001 nanoscience & nanotechnology ,Polarization (waves) ,Ferroelectricity ,0104 chemical sciences ,Capacitor ,phase transition ,Mechanics of Materials ,ddc:660 ,0210 nano-technology - Abstract
Antiferroelectric‐based dielectric capacitors are receiving tremendous attention for their outstanding energy‐storage performance and extraordinary flexibility in collecting pulsed powers. Nevertheless, the in situ atomic‐scale structural‐evolution pathway, inherently coupling to the energy storage process, has not been elucidated for the ultimate mechanistic understanding so far. Here, time‐ and atomic‐resolution structural phase evolution in antiferroelectric PbZrO3 during storage of energy from the electron‐beam illumination is reported. By employing state‐of‐the‐art negative‐spherical‐aberration imaging technique, the quantitative transmission electron microscopy study presented herein clarifies that the hierarchical evolution of polar oxygen octahedra associated with the unit‐cell volume change and polarization rotation accounts for the stepwise antiferroelectric‐to‐ferroelectric phase transition. In particular, an unconventional ferroelectric category—the ferrodistortive phase characteristic of a unique cycloidal polarization order—is established during the dynamic structure investigation. Through clarifying the atomic‐scale phase transformation pathway, findings of this work unveil a new territory to explore novel ferrodistortive phases in energy‐storage materials with the nonpolar‐to‐polar phase transitions.
- Published
- 2020
34. Modulated Structures in PbHfO3 Crystals at High-Pressure-High-Temperature Conditions
- Author
-
Alexey Filimonov, Andrzej Majchrowski, Paraskevas Parisiades, Yurii Bronwald, R. G. Burkovsky, Alexey Bosak, G. A. Lityagin, A E Fotiadi, Krystian Roleder, Daria Andronikova, and Maria Knjazeva
- Subjects
010302 applied physics ,Diffraction ,Radiation ,Materials science ,Analytical chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Diamond anvil cell ,High pressure ,0103 physical sciences ,Antiferroelectricity ,General Materials Science ,0210 nano-technology - Abstract
Lead hafnate single crystals were characterized using single crystal x-ray diffraction under simultaneous application of hydrostatic pressure and high temperatures. The information on the structure of two intermediate phases, situated between antiferroelectric and paraelectric phases in the pressure-temperature phase diagram, has been obtained. The lower-temperature intermediate phase is characterized by incommensurate displacive modulations in Pb sublattice. The higher-temperature intermediate phase is characterized by oxygen framework distortion, primarily in the form of anti-phase tilts of the oxygen octahedra, which is also present in the lower-temperature intermediate phase.
- Published
- 2018
35. Old and New Insights into Structure and Properties of Eu2[SiO4]
- Author
-
David Enseling, Joris van Slageren, Thomas Jüstel, Jürgen Köhler, Krystian Roleder, Iwona Lazar, Annette Bussmann-Holder, Heiko Bamberger, Thomas Schleid, Dariusz Kajewski, Christian Funk, and Jürgen Nuss
- Subjects
Diffraction ,Phase transition ,Materials science ,Birefringence ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Crystallography ,Hysteresis ,chemistry ,General Materials Science ,Orthorhombic crystal system ,0210 nano-technology ,Europium ,Single crystal ,Monoclinic crystal system - Abstract
Lemon-yellow single crystals of Eu2[SiO4] were obtained by reaction of elemental europium with Eu2O3 in the presence of SiO2 carried out in evacuated silica ampules at 1373 K for 48 h followed by constant cooling to room temperature with 120 K per hour. Eu2[SiO4] crystallizes at room temperature in the larnite-type structure of β-Ca2[SiO4] (monoclinic, P21/n) with parameters a = 565.02(5), b = 709.15(6), c = 975.84(8) pm, β = 92.614(3)° for Z = 4. At 452 K it undergoes a reversible phase transition to an incommensurate structure similar to the isotypic compounds Sr2[SiO4] and K2[SeO4]. The phase transition energy was determined to 0.54(2) J·g–1 by DSC measurements and temperature dependent birefringence measurements show that the phase transition exhibits a significant hysteresis. Refinements of the structure of Eu2[SiO4] based on single crystal X-ray diffraction data show that the high temperature modification crystallizes in the orthorhombic space group Pnma(α00)0ss with a = 710.16(6), b = 566.93(5), c ...
- Published
- 2018
36. An Unconventional Transient Phase with Cycloidal Order of Polarization in Energy-Storage Antiferroelectric PbZrO
- Author
-
Xian-Kui, Wei, Chun-Lin, Jia, Hong-Chu, Du, Krystian, Roleder, Joachim, Mayer, and Rafal E, Dunin-Borkowski
- Abstract
Antiferroelectric-based dielectric capacitors are receiving tremendous attention for their outstanding energy-storage performance and extraordinary flexibility in collecting pulsed powers. Nevertheless, the in situ atomic-scale structural-evolution pathway, inherently coupling to the energy storage process, has not been elucidated for the ultimate mechanistic understanding so far. Here, time- and atomic-resolution structural phase evolution in antiferroelectric PbZrO
- Published
- 2019
37. What makes the difference in perovskite titanates?
- Author
-
Annette Bussmann-Holder, Krystian Roleder, and Jae-Hyeon Ko
- Subjects
Phase transition ,Materials science ,Anharmonicity ,Ionic bonding ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Ion ,Condensed Matter::Materials Science ,Tetragonal crystal system ,Chemical physics ,Polarizability ,0103 physical sciences ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,General Materials Science ,010306 general physics ,0210 nano-technology ,Perovskite (structure) - Abstract
We have investigated in detail the lattice dynamics of five different perovskite titanates ATiO3 (A = Ca, Sr, Ba, Pb, Eu) where the A sites are occupied by +2 ions. In spite of the largely ionic character of these ions, the properties of these compounds differ substantially. They range from order/disorder like, to displacive ferroelectric, quantum paraelectric, and antiferromagnetic. All compounds crystallize in the cubic structure at high temperature and undergo structural phase transitions to tetragonal symmetry, partly followed by further transitions to lower symmetries. Since the TiO6 moiety is the essential electronic and structural unit, the question arises, what makes the significant difference between them. It is shown that the lattice dynamics of these compounds are very different, and that mode-mode coupling effects give rise to many distinct properties. In addition, the oxygen ion nonlinear polarizability plays a key role since it dominates the anharmonicity of these perovskites and determines the structural instability.
- Published
- 2018
38. Defect induced lattice instabilities and competing interactions in niobium doped lead zirconate single crystals
- Author
-
Rafal Sitko, Jae-Hyeon Ko, Iwona Lazar, Dariusz Kajewski, Annette Bussmann-Holder, Krystian Roleder, and Paweł Zajdel
- Subjects
Phase transition ,Materials science ,Niobium ,chemistry.chemical_element ,02 engineering and technology ,Dielectric ,01 natural sciences ,Zirconate ,Condensed Matter::Materials Science ,Condensed Matter::Superconductivity ,0103 physical sciences ,Materials Chemistry ,Antiferroelectricity ,Ceramic ,010306 general physics ,Condensed matter physics ,Mechanical Engineering ,Doping ,Metals and Alloys ,021001 nanoscience & nanotechnology ,chemistry ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Single crystal - Abstract
Influence of heterovalent Nb5+ doping of antiferroelectric PbZrO3 single crystal has been investigated. This kind of doping, producing defects in the perovskite matrix, influences the lattice instabilities responsible for phase transition at TC, and for inducing pre- and post-transitional effects. The dielectric, electromechanical, and optical properties were investigated. Opposite to their ceramic analogues, the investigated single crystals show a new phase transition and enlarged temperature ranges of lattice instabilities.
- Published
- 2018
39. Unexpected magnetism at high temperature and novel magneto-dielectric-elastic coupling in EuTiO 3 : A critical review
- Author
-
Annette Bussmann-Holder, Zurab Guguchia, Krystian Roleder, Hugo Keller, and Jürgen Köhler
- Subjects
Coupling ,Condensed matter physics ,Chemistry ,Magnetism ,Metals and Alloys ,02 engineering and technology ,Surfaces and Interfaces ,Dielectric ,Muon spin spectroscopy ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,0103 physical sciences ,Materials Chemistry ,010306 general physics ,0210 nano-technology ,Magneto ,Néel temperature ,Perovskite (structure) ,Phase diagram - Abstract
Perovskite oxides ABO3 offer a vast playground for applications and basic research. Especially multifunctionality is a frequently targeted aim, since the replacement of the A and/or B sublattice ions easily changes the properties of the system. Here we concentrate on the perovskite EuTiO3 (ETO) which was ignored by the scientific community for a long time. We review recent results on it and show that this compound provides many surprises which may offer novel device techniques and applications. In particular we demonstrate that far above its Neel temperature TN = 5.7 K magnetism exists and new magneto-dielectric-elastic coupling is at work. From capacitance and muon spin rotation (μSR) data we conclude that the phase diagram of ETO is much more complex than believed and a variety of new phases are described.
- Published
- 2017
40. Professor Wojciech Kuczyński (1941–2020)
- Author
-
Krystian Roleder, Arkadiusz C. Brańka, Jens Kreisel, and D. Dardas
- Subjects
Philosophy ,Art history ,General Materials Science ,Instrumentation - Abstract
Professor Wojciech Kuczynski, a Research Staff Member at the Institute of Molecular Physics of the Polish Academy of Sciences in Poznan, Poland, passed away on 5 December 2020.Professor Kuczynski w...
- Published
- 2021
41. Strong piezoelectric properties and electric-field-driven changes in domain structures in a PbZr0.87Ti0.13O3 single crystal
- Author
-
Krystian Roleder, Andrzej Majchrowski, Dariusz Kajewski, Iwona Lazar, and Andrzej Soszyński
- Subjects
010302 applied physics ,Birefringence ,Materials science ,Piezoelectric coefficient ,Polymers and Plastics ,Condensed matter physics ,Single crystal ,Piezoelectricity ,Metals and Alloys ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Polarization (waves) ,Phase coexistence ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Electric field ,0103 physical sciences ,Domain (ring theory) ,Ceramics and Composites ,Perovskites ,0210 nano-technology ,Perovskite (structure) ,Monoclinic crystal system - Abstract
PbZr1-xTixO3 perovskite materials, known as PZT, are highly applicable, mainly due to their extraordinary piezoelectric properties. Recently, a technology of PZT crystals growth has been elaborated and opened new investigation possibilities for these compounds. In this paper, we demonstrate a highly piezoelectric response in PbZr0.87Ti0.13O3 single crystal. Under the action of an electric field, the piezoelectric coefficient d33 turns out to be over 2500 pm V-1. The optical studies performed have proved a significant influence of the domain dynamics on such high-efficiency piezoelectric response. Monoclinic M and rhombohedral R phases have been observed in the lead zirconate-titanate crystals with a low Ti content. This coexistence of phases with different symmetries and dense domain walls are the primary sources of high piezoelectric response. We have observed that strong electric fields may act on randomly oriented polarization vectors so that the total piezoelectric activity disappears, and the unusual isotropization point near 250 °C appears.
- Published
- 2021
42. Surface–bulk interrelation in a PbZrO3single crystal
- Author
-
Annette Bussmann-Holder, Dariusz Kajewski, Jerzy Kubacki, and Krystian Roleder
- Subjects
010302 applied physics ,Phase transition ,Materials science ,Condensed matter physics ,Electrostriction ,Niobium ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Piezoelectricity ,Zirconate ,Crystallography ,chemistry ,Electric field ,0103 physical sciences ,Materials Chemistry ,0210 nano-technology ,Single crystal ,Solid solution - Abstract
In many cases, functionality is connected with the response of a material to the action of an external electric field. In oxidic perovskites, so widely used in practice, a disadvantage is their surface chemical instability when subjected to an electric field. That is why investigations of the influence of a high intensity alternating electric field on the phase transition temperatures and chemical properties of the surface and bulk of single crystals of PbZrO3 intentionally made defective by doping with niobium have been undertaken. It has been demonstrated that defects produced through the electro-degradation process make the low-field dielectric response a highly diffusive one, but they do not obscure the sharp phase transitions detected by temperature changes in the bulk piezoelectric and electrostrictive deformation around the critical temperature. Based on XPS spectra, the types of defects at the surface and in the bulk of as-grown single crystals caused by the electric field action are identified. It has been shown that the surface–bulk interrelation in ferroic lead zirconate and solid solutions based on this material has to be taken into account while trying to use them as high quality functional materials.
- Published
- 2017
43. Editors Note
- Author
-
Andrzej Szytuła, Stanisław Baran, Janusz Chruściel, Wojciech Zając, and Krystian Roleder
- Subjects
General Materials Science ,Instrumentation - Published
- 2019
44. Clarification of the Phase Diagram of PbHfO3 in Pressure-temperature Space
- Author
-
Gaston Garbariano, R. G. Burkovsky, Andrzej Majchrowski, Yurii Bronvald, Maria A. Kniazeva, Krystian Roleder, Alexey Filimonov, Daria Andronikova, Alexander E. Ganzha, Paraskevas Parisiades, and Georgii Lityagin
- Subjects
Diffraction ,Phase transition ,Materials science ,Condensed matter physics ,Hydrostatic pressure ,macromolecular substances ,02 engineering and technology ,Soft modes ,021001 nanoscience & nanotechnology ,01 natural sciences ,Octahedron ,Phase (matter) ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Superstructure (condensed matter) ,Phase diagram - Abstract
We report the high-temperature and high-pressure single-crystal x-ray diffraction study of PbHfO3. The increase of pressure enables an additional intermediate phase, located between the cubic and incommensurate phases, and characterized by superstructure reflections indicating the presence of anti-phase oxygen octahedral tilts. The temperature-dependent diffuse peak at an incommensurate position is much better pronounced at higher pressures (~ 2 GPa) than at lower pressures (~ 1.1 GPa), which we interpret as enhancing of the incommensurate soft mode on pressure increase. Several peculiarities in the behavior of superstructural reflections at M- and X- points are reported and discussed.
- Published
- 2019
45. Triggered incommensurate transition in PbHfO3
- Author
-
Alexey Filimonov, G. A. Lityagin, A. I. Rudskoy, Andrzej Majchrowski, Alexei Bosak, Krystian Roleder, Daria Andronikova, Iurii Bronwald, S. M. Souliou, Julita Piecha, R. G. Burkovsky, and Alexander K. Tagantsev
- Subjects
Physics ,Phase transition ,Condensed matter physics ,Lattice (group) ,Order (ring theory) ,02 engineering and technology ,Soft modes ,021001 nanoscience & nanotechnology ,Coupling (probability) ,01 natural sciences ,Ferroelectricity ,Landau theory ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Perovskite (structure) - Abstract
We report a type of structural phase transitions in dielectric materials: the triggered incommensurate (IC) transition. We demonstrate evidence for such a transition in the perovskite antiferroelectric ${\mathrm{PbHfO}}_{3}$ by means of single-crystal x-ray diffraction, diffuse, and inelastic-scattering experiments, which we interpret using the Landau theory of phase transitions. This transition is not driven by an IC soft mode, as is the case for the majority of IC dielectrics, but by the soft mode associated with a different, coexisting order parameter related to antiferrodistortive (AFD) tilts of the oxygen octahedra. When cooling from the high-temperature cubic phase these two order parameters are established simultaneously and discontinuously at ${T}_{\text{IC}}\ensuremath{\approx}468$ K. Two lattice instabilities are present in the cubic phase: AFD instability with critical temperature ${T}_{0}\ensuremath{\approx}441$ K and ferroelectric instability with ${T}_{0}\ensuremath{\approx}408$ K. The IC instability is absent. The analysis of the transition mechanism within the Landau theory of coupled order parameters indicates that the transition is of triggered character, conditioned upon the attractive biquadratic coupling between the IC modulation and the AFD octahedral tilts, and is driven by the AFD soft mode.
- Published
- 2019
46. Incommensurate crystal structure of PbHfO
- Author
-
Alexei, Bosak, Volodymyr, Svitlyk, Alla, Arakcheeva, Roman, Burkovsky, Vadim, Diadkin, Krystian, Roleder, and Dmitry, Chernyshov
- Abstract
Controversy in the description/identification of so-called intermediate phase(s) in PbHfO
- Published
- 2019
47. Precursor Phenomena of Barium Titanate Single Crystals Grown Using a Solid-State Single Crystal Growth Method Studied with Inelastic Brillouin Light Scattering and Birefringence Measurements
- Author
-
Jae-Hyeon Ko, Ho-Yong Lee, Iwona Lazar, Soo Han Oh, and Krystian Roleder
- Subjects
BaTiO3 ,Materials science ,Barium Compounds ,Pharmaceutical Science ,Crystal growth ,acoustic property ,02 engineering and technology ,01 natural sciences ,Article ,Analytical Chemistry ,Crystal ,lcsh:QD241-441 ,chemistry.chemical_compound ,symbols.namesake ,lcsh:Organic chemistry ,0103 physical sciences ,Drug Discovery ,barium titanate ,Physical and Theoretical Chemistry ,010306 general physics ,Birefringence ,Brillouin Spectroscopy ,Condensed matter physics ,Spectrum Analysis ,Organic Chemistry ,Temperature ,021001 nanoscience & nanotechnology ,Dynamic Light Scattering ,precursor phenomena ,Brillouin zone ,chemistry ,Barium ,Chemistry (miscellaneous) ,Barium titanate ,symbols ,Brillouin spectroscopy ,Molecular Medicine ,Crystallization ,0210 nano-technology ,Raman spectroscopy ,Single crystal - Abstract
The nature of precursor phenomena in the paraelectric phase of ferroelectrics is one of the main questions to be resolved from a fundamental point of view. Barium titanate (BaTiO3) is one of the most representative perovskite-structured ferroelectrics intensively studied until now. The pretransitional behavior of BaTiO3 single crystal grown using a solid-state crystal growth (SSCG) method was investigated for the first time and compared to previous results. There is no melting process in the SSCG method, thus the crystal grown using a SSCG method have inherent higher levels of impurity and defect concentrations, which is a good candidate for investigating the effect of crystal quality on the precursor phenomena. The acoustic, dielectric, and piezoelectric properties, as well as birefringence, of the SSCG-grown BaTiO3 were examined over a wide temperature range. Especially, the acoustic phonon behavior was investigated in terms of Brillouin spectroscopy, which is a complementary technique to Raman spectroscopy. The obtained precursor anomalies of the SSCG-grown BaTiO3 in the cubic phase were similar to those of other single crystals, in particular, of high-quality single crystal grown by top-seeded solution growth method. These results clearly indicate that the observed precursor phenomena are common and intrinsic effect irrespective of the crystal quality.
- Published
- 2018
48. A contribution to understanding the complex phase diagram of PZT compounds
- Author
-
Dariusz Kajewski, Iwona Lazar, Krystian Roleder, Andrzej Soszyński, Andrzej Majchrowski, and Janusz Koperski
- Subjects
010302 applied physics ,Materials science ,02 engineering and technology ,Dielectric ,Trigonal crystal system ,PZT compound ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Piezoelectricity ,Electronic, Optical and Magnetic Materials ,Crystal ,Crystallography ,0103 physical sciences ,0210 nano-technology ,Phase diagram ,Monoclinic crystal system - Abstract
We have succeeded to grow single PbZr1-xTixO3 (PZT) crystal with Ti content of the order of x = 0.13. PZT compound with such Ti concentration is characterised by structural coexistence of the rhombohedral and monoclinic structures at each temperature below TC. It seems that investigations of the dielectric, piezoelectric and optical properties confirm this highly complicated co-existence.
- Published
- 2016
49. New features from transparent thin films of EuTiO3
- Author
-
R. K. Kremer, Gennady Logvenov, Alexander Boris, Benjamin Stuhlhofer, Jürgen Köhler, Annette Bussmann-Holder, D. Pröpper, Krystian Roleder, and M. Górny
- Subjects
Phase transition ,Birefringence ,Materials science ,business.industry ,Band gap ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Magnetic susceptibility ,Optics ,0103 physical sciences ,Antiferromagnetism ,Optoelectronics ,General Materials Science ,Multiferroics ,Thin film ,010306 general physics ,0210 nano-technology ,business ,Instrumentation ,Perovskite (structure) - Abstract
The almost multiferroic perovskite EuTiO3 (ETO) has been prepared as films on substrates of SrTiO3. For all prepared film thicknesses highly transparent insulating films with atomically flat surfaces and excellent orientation have been grown. They were characterized by X-ray diffraction, magnetic susceptibility and birefringence measurements and found to exhibit bulk properties, namely an antiferromagnetic transition at TN = 5.1 K and a structural transition at TS = 282 K. The latter could only be identified due to the high transparency of the samples since the optical band gap is of the order of 4.5 eV and larger than observed before for any bulk and thin film samples.
- Published
- 2016
50. In memory of Ihor Stasyuk
- Author
-
Jens Kreisel and Krystian Roleder
- Subjects
Art history ,General Materials Science ,Instrumentation - Abstract
Professor Ihor Stasyuk, a prominent scientist and lecturer passed away on 16 September 2019. He significantly contributed with remarkable results to the quantum many-body physics and to the theoret...
- Published
- 2020
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.