posted on 2023-12-22, 20:07authored byYu-Bo Huang, Jun-Qiu Li, Wen-Huang Xu, Wenwei Zheng, Xiaopeng Zhang, Kai-Ge Gao, Tianchi Ji, Taisuke Ikeda, Takumi Nakanishi, Shinji Kanegawa, Shu-Qi Wu, Sheng-Qun Su, Osamu Sato
Light,
a nondestructive and remotely controllable external stimulus,
effectively triggers a variety of electron-transfer phenomena in metal
complexes. One prime example includes using light in molecular cyanide-bridged
[FeCo] bimetallic Prussian blue analogues, where it switches the system
between the electron-transferred metastable state and the system’s
ground state. If this process is coupled to a ferroelectric-type phase
transition, the generation and disappearance of macroscopic polarization,
entirely under light control, become possible. In this research, we
successfully executed a nonpolar-to-polar phase transition in a trinuclear
cyanide-bridged [Fe2Co] complex crystal via directional electron transfer. Intriguingly,
by exposing the crystal to the wavelength of light785 nmwithout
any electric fieldwe can drive this ferroelectric phase transition
to completely depolarize the crystal, during which a measurable electric
current response can be detected. These discoveries signify an important
step toward the realization of fully light-controlled ferroelectric
memory devices.