Erhart, Paul ; Albe, Karsten (2007)
Thermodynamics of mono- and di-vacancies in barium titanate.
In: Journal of Applied Physics, 102 (8)
doi: 10.1063/1.2801011
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The dependence of the electrical conductivity on the oxygen partial pressure is calculated for the prototypical perovskite BaTiO3 based on data obtained from first-principles calculations within density functional theory. The equilibrium point defect concentrations are obtained via a self-consistent determination of the electron chemical potential. This allows one to derive charge carrier concentrations for a given temperature and chemical environment and eventually the electrical conductivity. The calculations are in excellent agreement with experimental data if an accidental acceptor dopant level of 1017 cm3 is assumed. It is shown that doubly charged oxygen vacancies are accountable for the high-temperature n-type conduction under oxygen-poor conditions. The high-temperature p-type conduction observed at large oxygen pressures is due to barium vacancies and titanium-oxygen divacancies under Ti- and Ba-rich conditions, respectively. Finally, the connection between the present approach and the mass-action law approach to point defect thermodynamics is discussed.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2007 |
| Autor(en): | Erhart, Paul ; Albe, Karsten |
| Art des Eintrags: | Bibliographie |
| Titel: | Thermodynamics of mono- and di-vacancies in barium titanate |
| Sprache: | Englisch |
| Publikationsjahr: | 30 Oktober 2007 |
| Verlag: | American Institute of Physics |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Applied Physics |
| Jahrgang/Volume einer Zeitschrift: | 102 |
| (Heft-)Nummer: | 8 |
| DOI: | 10.1063/1.2801011 |
| Kurzbeschreibung (Abstract): | The dependence of the electrical conductivity on the oxygen partial pressure is calculated for the prototypical perovskite BaTiO3 based on data obtained from first-principles calculations within density functional theory. The equilibrium point defect concentrations are obtained via a self-consistent determination of the electron chemical potential. This allows one to derive charge carrier concentrations for a given temperature and chemical environment and eventually the electrical conductivity. The calculations are in excellent agreement with experimental data if an accidental acceptor dopant level of 1017 cm3 is assumed. It is shown that doubly charged oxygen vacancies are accountable for the high-temperature n-type conduction under oxygen-poor conditions. The high-temperature p-type conduction observed at large oxygen pressures is due to barium vacancies and titanium-oxygen divacancies under Ti- and Ba-rich conditions, respectively. Finally, the connection between the present approach and the mass-action law approach to point defect thermodynamics is discussed. |
| Freie Schlagworte: | ab initio calculations, barium compounds, carrier density, chemical potential, density functional theory, electrical conductivity, vacancies (crystal) |
| Zusätzliche Informationen: | SFB 595 C1 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialmodellierung Zentrale Einrichtungen DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > C - Modellierung 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 11 Fachbereich Material- und Geowissenschaften DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche DFG-Sonderforschungsbereiche (inkl. Transregio) |
| Hinterlegungsdatum: | 15 Aug 2011 12:47 |
| Letzte Änderung: | 05 Mär 2013 09:51 |
| PPN: | |
| Sponsoren: | This project was funded by the Sonderforschungsbereich 595 “Fatigue in functional materials” of the Deutsche Forschungsgemeinschaft. |
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