Gröting, Melanie ; Hayn, Silke ; Albe, Karsten (2011)
Chemical order and local structure of the lead-free relaxor ferroelectric (Na1/2Bi1/2)TiO3.
In: Journal of Solid State Chemistry, 184 (8)
doi: 10.1016/j.jssc.2011.05.044
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The A-site mixed perovskite sodium bismuth titanate (Na1/2Bi1/2)TiO3 (NBT) is investigated by means of first-principles calculations based on density functional theory. By studying different geometries with varying occupations of the A-site, the influence of chemical order on the thermodynamic stability and local structure is explored. We find that the hybridization of Bi 6sp with O 2p-states leads to stereochemically active Bi3+ lone pairs and increases the stability of structures with high Bi concentrations in {001}-planes. This goes along with displacive disorder on the oxygen sublattice, which up to now has been neglected in experimental studies. The calculated ordering energies are, however, small as compared to the thermal energy and therefore only short-range chemical order can be expected in experiments. Thus, it is conceivable that chemically ordered local areas can act as nucleation sites for polar nano-regions, which would explain the experimentally observed relaxor behavior of NBT.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2011 |
| Autor(en): | Gröting, Melanie ; Hayn, Silke ; Albe, Karsten |
| Art des Eintrags: | Bibliographie |
| Titel: | Chemical order and local structure of the lead-free relaxor ferroelectric (Na1/2Bi1/2)TiO3 |
| Sprache: | Englisch |
| Publikationsjahr: | August 2011 |
| Verlag: | Elsevier Science Publishing Company |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Solid State Chemistry |
| Jahrgang/Volume einer Zeitschrift: | 184 |
| (Heft-)Nummer: | 8 |
| DOI: | 10.1016/j.jssc.2011.05.044 |
| URL / URN: | http://www.sciencedirect.com/science/article/pii/S0022459611... |
| Kurzbeschreibung (Abstract): | The A-site mixed perovskite sodium bismuth titanate (Na1/2Bi1/2)TiO3 (NBT) is investigated by means of first-principles calculations based on density functional theory. By studying different geometries with varying occupations of the A-site, the influence of chemical order on the thermodynamic stability and local structure is explored. We find that the hybridization of Bi 6sp with O 2p-states leads to stereochemically active Bi3+ lone pairs and increases the stability of structures with high Bi concentrations in {001}-planes. This goes along with displacive disorder on the oxygen sublattice, which up to now has been neglected in experimental studies. The calculated ordering energies are, however, small as compared to the thermal energy and therefore only short-range chemical order can be expected in experiments. Thus, it is conceivable that chemically ordered local areas can act as nucleation sites for polar nano-regions, which would explain the experimentally observed relaxor behavior of NBT. |
| Freie Schlagworte: | Perovskite, Relaxor, NBT, Chemical order, Local structure |
| Zusätzliche Informationen: | SFB 595 C1 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 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 DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > C - Modellierung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung Zentrale Einrichtungen DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche DFG-Sonderforschungsbereiche (inkl. Transregio) |
| Hinterlegungsdatum: | 22 Feb 2012 16:26 |
| Letzte Änderung: | 05 Mär 2013 09:58 |
| PPN: | |
| Sponsoren: | This work has been financially supported by the LOEWE-Center “Adaptronics—Research, Innovation, Application” and by the DFG Center of Excellence 595 “Electrical Fatigue in Functional Materials”., Moreover, this work was made possible by grants for computing time on supercomputers at HRZ Darmstadt. |
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