Solution Stability of Rare-Earth Elements in Barium Titanate: Theoretical Study

抄録

  We performed first-principles theoretical calculations to investigate systematically the solution stability of rare-earth elements (REs), i.e., Sm, Gd, Dy and Er, doped in the perovskite oxide BaTiO₃ in various phase conditions and chemical compositions, in order to clarify the dependence of the fabrication condition on the selectivity of the substitution site. We found that Gd, Dy and Er occupy both the Ba and Ti sites and that only Sm tends to occupy the Ba site. However, the substitution of Sm at the Ti site occurs under the condition of oxidative atmosphere and Ba-rich composition. Further, we also examined the interaction between REs and the O vacancies in BaTiO₃. The mechanism for suppressing the migration of O vacancies by REs is discussed.