Gröting, Melanie ; Kornev, Igor ; Dkhil, Brahim ; Albe, Karsten (2012)
Pressure-induced phase transitions and structure of chemically ordered nanoregions in the lead-free relaxor ferroelectric Na_{1/2}Bi_{1/2}TiO_{3}.
In: Physical Review B, 86 (13)
doi: 10.1103/PhysRevB.86.134118
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
We investigate the phase stability of Na1/2Bi1/2TiO3, a prototype lead-free relaxor material, under pressure. By means of total energy calculations within density functional theory, we study the pressure stability of several structures with polar and antipolar distortions, in-phase and out-of-phase tilts, and different chemically ordered configurations. Under positive (compressive) pressure an orthorhombic Pbnm-like phase is stabilized above 3 GPa. At negative (tensile) pressure a non-tilted polar P4mm-like phase is stable. At zero pressure two phases are coexisting. The local chemical configuration determines whether the high-pressure Pbnm-like or another tilted and polar R3c-like structure is favored. Thus, two different variants of pressure phase diagrams depending on the cation arrangement are obtained, which raises the question of the existence of a mixed phase ground state in the disordered system. We discuss the stability of the mixed phase state in terms of lattice and tilt misfits and possible shapes and ferroic properties of the coexisting regions with different average structures. Our results clearly support the view that there are chemically ordered nanoregions with their own local ferroic properties embedded in a chemically disordered ferroelectric matrix representing the ground state.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2012 |
| Autor(en): | Gröting, Melanie ; Kornev, Igor ; Dkhil, Brahim ; Albe, Karsten |
| Art des Eintrags: | Bibliographie |
| Titel: | Pressure-induced phase transitions and structure of chemically ordered nanoregions in the lead-free relaxor ferroelectric Na_{1/2}Bi_{1/2}TiO_{3} |
| Sprache: | Englisch |
| Publikationsjahr: | 24 Oktober 2012 |
| Verlag: | American Physical Society |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Physical Review B |
| Jahrgang/Volume einer Zeitschrift: | 86 |
| (Heft-)Nummer: | 13 |
| DOI: | 10.1103/PhysRevB.86.134118 |
| Kurzbeschreibung (Abstract): | We investigate the phase stability of Na1/2Bi1/2TiO3, a prototype lead-free relaxor material, under pressure. By means of total energy calculations within density functional theory, we study the pressure stability of several structures with polar and antipolar distortions, in-phase and out-of-phase tilts, and different chemically ordered configurations. Under positive (compressive) pressure an orthorhombic Pbnm-like phase is stabilized above 3 GPa. At negative (tensile) pressure a non-tilted polar P4mm-like phase is stable. At zero pressure two phases are coexisting. The local chemical configuration determines whether the high-pressure Pbnm-like or another tilted and polar R3c-like structure is favored. Thus, two different variants of pressure phase diagrams depending on the cation arrangement are obtained, which raises the question of the existence of a mixed phase ground state in the disordered system. We discuss the stability of the mixed phase state in terms of lattice and tilt misfits and possible shapes and ferroic properties of the coexisting regions with different average structures. Our results clearly support the view that there are chemically ordered nanoregions with their own local ferroic properties embedded in a chemically disordered ferroelectric matrix representing the ground state. |
| Zusätzliche Informationen: | SFB 595 C1 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialmodellierung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > C - Modellierung > Teilprojekt C1: Quantenmechanische Computersimulationen zur Elektronen- und Defektstruktur oxidischer Materialien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > C - Modellierung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung 11 Fachbereich Material- und Geowissenschaften Zentrale Einrichtungen DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche DFG-Sonderforschungsbereiche (inkl. Transregio) |
| Hinterlegungsdatum: | 30 Okt 2012 13:07 |
| Letzte Änderung: | 05 Mär 2013 10:03 |
| PPN: | |
| Sponsoren: | This work has been financially supported by the LOEWECenter “Adaptronics - Research, Innovation, Application” and by the DFG Collaborative Research Center SFB 595 “Electrical Fatigue in Functional Materials.”, Moreover, this work was made possible by grants for computing time on supercomputers at HRZ Darmstadt., DAAD is acknowledged for supporting the stay of one of us (M.G.) at École Centrale Paris. |
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