Organic ferroelectrics are highly desirable for their light weight, mechanical flexibility and biocompatibility. However,t he rational design of organic ferroelectrics has always faced great challenges.A nilinium bromide (AB) has two structures reported in the Cambridge Crystallographic Data Centre,w hich might be an mmmF2/m type ferroelastic (AB-1). When we studied its ferroelasticity,wewere surprised to discover that there was another crystal (AB-2) in H 2 O besides this one,a nd they were very difficult to separate.B y changing the solvent, we found that AB-1 crystals could be formed in ethanol, where ferroelastic domains were visualized by polarized light microscopy, and AB-2 crystals could be obtained from various crystallization solvents of methanol, isopropanol, N-butanol, acetonitrile,d imethyl sulfoxide,a nd N,N-dimethylformamide,w hich undergo af erroelectric phase transition with mm2Fm, showing clear ferroelectricity in two phases.T oo ur knowledge,t he regulation of ferroelasticity to ferroelectricity by solvent selective effect is unprecedented in the field of ferroelectrics.This work reveals the important role of solvent effect in organic ferroelectrics.

Multifunctional switching materials show great potential for applications in sensors, smart switches, and other fields due to the ability of integrating different physical channels in one single device. However, multifunctional...

As a feasible lead-free scheme, organic-inorganic hybrid double perovskite shows many excellent properties, including ferroelectricity, ferroelasticity, self-powered circularly polarized light detection and so on. In this work, the solid-to-solid structural...

Organic ferroelectrics are highly desirable for their light weight, mechanical flexibility and biocompatibility. However,t he rational design of organic ferroelectrics has always faced great challenges.A nilinium bromide (AB) has two structures reported in the Cambridge Crystallographic Data Centre,w hich might be an mmmF2/m type ferroelastic (AB-1). When we studied its ferroelasticity,wewere surprised to discover that there was another crystal (AB-2) in H 2 O besides this one,a nd they were very difficult to separate.B y changing the solvent, we found that AB-1 crystals could be formed in ethanol, where ferroelastic domains were visualized by polarized light microscopy, and AB-2 crystals could be obtained from various crystallization solvents of methanol, isopropanol, N-butanol, acetonitrile,d imethyl sulfoxide,a nd N,N-dimethylformamide,w hich undergo af erroelectric phase transition with mm2Fm, showing clear ferroelectricity in two phases.T oo ur knowledge,t he regulation of ferroelasticity to ferroelectricity by solvent selective effect is unprecedented in the field of ferroelectrics.This work reveals the important role of solvent effect in organic ferroelectrics.