Ferroelectricity in perovskite realized by switchable skewed conformation

Abstract

Ferroelectric materials have broad application prospects in photovoltaics, energy storage, information storage and other fields, and it is always a challenge to obtain ferroelectric materials through rational molecular design. Noncentrosymmetric crystallization, directional arrangement of dipoles and appropriate flipping barrier are all difficult problems in building ideal ferroelectric materials. In this article, a novel hybrid material TDMHACdCl3 (1, TDMHA+ is N-(tert-butyl)-N,N-dimethylhydroxylammonium) with ferroelectric property was successfully synthesized and characterized. A CH3/OH substitution strategy was employed to construct the hydrogen bond between the organic cation and the inorganic framework, deflecting the dipole moment direction of the cation. To minimize the energy of the crystal lattice, hydrogen bonds compete with the cation conformation, causing the cations to deviate from the optimal conformation, allowing the dipoles to be oriented in one direction. The crystal structure and quantum chemical calculations were thoroughly discussed to reveal the origin of the ferroelectric property in this work. We believe that our design will contribute to the discovery of more ferroelectric materials.