A new 12L-hexagonal perovskite Cs4Mg3CaF12: structural transition derived from the partial substitution of Mg2+ with Ca2+

Abstract

A new 12L-hexagonal perovskite Cs₄Mg₃CaF₁₂ was synthesized using an open high-temperature solution method. It crystallizes in the trigonal space group Rm (no. 166) with lattice constants a = 6.2196(9) Å, c = 29.812(9) Å, Z = 3. Cs₄Mg₃CaF₁₂ is changed from the cubic phase CsMgF₃ by replacing 25% Mg²⁺ with Ca²⁺. The changes derived from the substitution and the structural comparison between Cs₄Mg₃CaF₁₂ and other perovskites are discussed in this paper. Thermal analysis, infrared spectroscopy, and electronic structure calculations were performed on the reported material.