Structural Phase Transitions and Dielectric Switching in a Series of Organic‐Inorganic Hybrid Perovskites ABX₃ (X=ClO₄⁻ or BF₄⁻)

Abstract

Abstract A series of organic‐inorganic hybrid perovskites ABX 3 (A=diprotonated 1,4‐diazabicyclo[2.2.2]octane or piperazine; B=Na + or K + ; X=ClO 4 − or BF 4 − ) has been synthesized. They feature a cubic cage‐like host‐guest structures of which A is the cationic guest residing in the anionic cage B 8 X 12 , B is the vertex of the cage with variable coordination numbers between six and twelve, and X is the bridging ligand with mono‐ and/or bidentate coordination modes. The extended Goldschmidt tolerance factor t is used to describe the phase stability of the compounds. Differential scanning calorimetry, variable‐temperature structural analyses, and dielectric measurements reveal that order‐disorder transitions of the A guest and/or X bridging ligand are supposed to be responsible for structural phase transitions and dielectric switching in the compounds.