Preparation and Photostriction Properties of BiFeO₃-BaTiO₃ Ceramics

Under illumination by 405, 520 and 655 nm monochromatic visible light (light intensity of 30 kW/m²), large photostriction (ΔL/L) of 0.19%, 0.13% and 0.26% for 67BiFeO₃-33BaTiO₃(67BF-33BT) lead-free ferroelectric ceramics are obtained, respectively. By studying the ferroelectric and photoelectric properties in conjunction with in situ Raman spectroscopy, it is found that the photostrictive effect of 67BF-33BT is not caused by the electrical strain induced by abnormal photovoltaic voltage, but related to the optical induced oxygen octahedral distortion. The 67BF-33BT lead-free ferroelectric material with excellent photostrictive response in the visible light region is expected to play an important role in the field of optical drive electromechanical devices.