R2: Crystal structure, crystal chemistry, physical properties of minerals, crystal growth and applied mineralogy

[R2-09] Solid solubilities of Na⁺ and K⁺ in perovskite type SrTiO₃

Ryogo KITAI², *Takaya NAGAI¹, Jun KAWANO¹, Ayako Shinozaki¹ (1. Hokkaido Univ. Faculty SCi., 2. Hokkaido Univ. School SCi.)

Keywords:perovskite structure, SrTiO3, Na, K, oxygen vacancy

In this study, we report the results of synthetic experiments investigating the solid solubilities of Na⁺ and K⁺ in perovskite-type SrTiO₃. According to Shannon (1976), the ionic radii of Na⁺ and K⁺ at a 6-coordinate site are significantly larger than that of Ti⁴⁺, while their ionic radii at a 12-coordinate site are comparable to that of Sr²⁺. Assuming that Na⁺ and K⁺ only exchange with Sr²⁺, this solid solution mechanism would result in the formation of oxygen vacancies.