Abstract: The structures of perovskites in the system CaTiO₃-SrTiO₃ were measured and refined at room temperature by X-ray powder diffraction. The sequence of phase transitions for Ca_1-xSr_xTiO₃(0≤x≤1), found with increasing Sr content, is orthorhombic Pbnm, orthorhombic Bmmb, tetragonal I4/mcm and cubic Pm3m. The boundaries of phase transitions are at x=0.45(5)for Pbnm-Bmmb, x=0.65(5) for Bmmb-I4/mcm and x=0.92(2) for Pm3m, respectively.

Key words: powder X-ray, phase transition, perovskite, CaTiO₃-SrTiO₃

摘要： 利用粉晶X射线在室温下对CaTiO₃-SrTiO₃体系中钙钛矿型化合物进行了系统测量和结构精化。随着Sr含量的增加，Ca_1-xSr_xTiO₃(0≤x≤1)从斜方晶系的Pbnm结构依次转变为斜方Bmmb, 四方I4/mcm和等轴Pm3m结构。其相转变边界依次为：Pbnm-Bmmb x=0.45(5)，Bmmb-I4/mcm x=0.65(5)和I4/mcm-Pm3m x=0.92(2)。

关键词: 粉晶X射线, 相转变, 钙钛矿, CaTiO₃-SrTiO₃