Enantiomeric perovskite with a dual phase transition at high temperature

Abstract

Temperature-dependent physical switching materials have been of wide concern for materials chemists. Among them, switchable dielectric perovskite materials have shown huge application potential in the fields of sensing, information storage, and electronics. In particular, for better practical application, obtaining dual-phase-change switching materials with a high phase transition temperature (T_c) is still a worthwhile issue to study. In this work, we synthesized chiral hybrid organic inorganic perovskites, namely, (R)-, (S)- and (rac)-N,N-dimethyl-3-fluoropyrrolidinium (DMFP) CdCl₃. The enantiomeric compound undergoes a dual phase transition with a T_c of 460 K and 367 K. T_c significantly increased by 28 K from 411 K of (N,N-dimethyl pyrrolidinium) (DMP) CdCl₃ to 439 K of (rac)-DMFP CdCl₃. Besides, (R) and (S)-DMFP CdCl₃ are the first example of chiral perovskites that show dual T_c with robust switching dielectric characteristics. This work could be a pathway for designing multifunctional chiral perovskite-type switchable materials.