Large electrostrain with nearly-vanished hysteresis in eco-friendly perovskites by building coexistent glasses near quadruple point

One of the key questions in the development of eco-friendly piezoelectrics lies in how to achieve large hysteresis-free electrostrain responses in a facile and effective manner, to meet the requirements of high-precision electromechanical devices. Here, through integrating phase-field modeling and experimental approach, a highly effective strategy is proposed for large electrostrain outputs with negligible hysteresis in lead-free perovskite oxide ferroelectrics, by building coexistent glasses with diverse local symmetries near a quadruple point rendering low energy barriers between different polar states. Guided by phase-field simulations, a superior electrostrain of ~ 0.21% with nearly-zero hysteresis is obtained at the constructed glasses region near the quadruple point of Bi-doped Ba(Zr_0.2Ti_0.8)O₃-x(Ba_0.7Ca_0.3)TiO₃ ceramics, outperforming almost state-of-the-art lead-free piezoelectric substitutions when taking both electrostrain and hysteresis into account. The strategy of building coexistent glasses near the quadruple point provides a novel design paradigm for high-performance piezoelectric materials in the application of high-precision actuators.