Structure And Dielectric Properties Of Organic-Inorganic Hybrid Compounds Based On Metal Halides

Compared to conventional inorganic dielectrics and ferroelectrics,organic-inorganic hybrid compounds have gained increasing scientific attention due to the advantages of facile preparation and processibility,mechanical flexibility,and environmental friendliness.In search of a new range of dielectrics and ferroelectrics,we have designed and synthesized new organic-inorganic hybrid crystals materials,and measured and studied their crystal structure and dielectric characteristics.In this paper,the quaternary ammonium salt and cyclic amine were used as raw materials.Then mixed them with metal halide to obtain ten new organic-inorganic hybrid compounds:[TMAA]₃[Bi₂Cl₉]?1??[C₆H₁₄N][CdCl₃]?2??[C₆H₁₅NBr]₂[CdBr₄]?3??[C₆H₁₅NBr]₂[ZnBr₄]?4??[C₈H₂₀NO₂]₂[Sb₂Cl₈]?5??[C₇H₁₁N₂]₂[Cd₃Cl₈]?6??[C₁₇H₃₉O₇N₃][CdCl₄]?H₂O??7??[C₅H₇N₃Cl]₃[Sb₂Br₉]?8??[C₁₀H₂₄N₂][CuCl₄]?9??[C₁₀H₂₄N₂][CdBr₄]?10?.The crystal structures and dielectric properties of ten compounds were measured.The organic ionic plastic crystal?OIPC?1 has a reversible structural phase transition triggered by linear/propeller/ball three forms motion at high temperature.The dielectric constant exhibits switchable bistability in the vicinity of phase transition temperature and step-like changes,and has scarce multi-axial property.The ionic co-crystal 8 undergoes a reversible structural phase transition,the anion and cation as a stator and a pendulum-like rotor respectively,which is induced by the order-disorder transition.The dielectric constant of 8 exhibits a step-like change near the phase transition temperature and dielectric bistability.Herein,the structural changes of the cations between high and low temperature,and the results of DSC further demonstrate that phase transitions exist in compounds 1 and 8.Other compounds were measured,however,they did not exist phase transitions.