Salicylideneaniline is a Photoswitchable Ferroelectric Crystal.

Since the discovery of the first ferroelectric Rochelle salt, most ferroelectrics have been investigated showing thermally triggered symmetry-breaking phase transition. Although photochromism arising from geometrical isomerization has been reported earlier in 1867, such photoswitchable ferroelectric crystals have scarcely been developed to date. Herein, we report that salicylideneaniline is a photochromic ferroelectric crystal. Upon photoirradiation, the dielectric constant shows obvious switching between high and low dielectric states, and more importantly, the ferroelectric polarization demonstrates quickly and reversibly switching. This work opens the gate of developing photoswitchable ferroelectrics, which holds great potential for applications in optically controlled smart devices.