A Metal‐Free Molecular Ferroelectric [4‐Me‐cyclohexylamine]ClO4 Introduced by Boat and Chair Conformations of Cyclohexylamine

Abstract

AbstractOrganic ferroelectrics have received a great deal of interest due to their exclusive properties. However, organic ferroelectrics have not been fully explored, which hinders their practical application. Here, we presented a novel metal‐free organic molecular ferroelectric [4‐MCHA][ClO4] (1) (4‐MCHA=trans‐4‐methylcyclohexylamine), which exhibits an above‐room‐temperature of 328 K. Strikingly, the single crystal structure analysis of 1 shows that the driving force of phase transition is related to the interesting chair‐boat conformation change of 4‐MCHA cation, in addition to the order‐disorder transition of ClO4− anion. Using piezoelectric response force microscopy (PFM), the presence of domains and the implemented polarization switching were clearly observed, which explicitly determined the presence of room‐temperature ferroelectricity of 1. As far as we know, the ferroelectric phase transition mechanism attributed to the conformational change in a trans isomeric cation is very rare. This research enriched the path of designing ferroelectric materials and smart materials.