Papers by Author: Shinji Tsuneyuki

Abstract: Structural changes induced by oxygen vacancies in tetragonal phase BaTiO₃ are studied with first principles calculations within density functional theory. In our calculations, the incorporation of oxygen vacancies greatly decreases c/a ratio of the tetragonal phase BaTiO₃, and a phase transition from tetragonal to cubic phase occurs when the incorporation of the oxygen vacancies reaches about 4%. Our results also shows that the generation of the oxygen vacancies slightly increases the volume of BaTiO₃, and the increases are typically less than 0.5% even in heavily reduced conditions.