Structural phase transition, relaxor behavior, and ultra-low strain hysteresis in BaTiO₃ ceramics modified by BiYO₃

In this study, the structural properties, phase transition, relaxor behavior, and strain properties of (1−x)BaTiO3‒xBiYO3 (x = 0.02‒0.15 mol) ceramics were investigated. The room temperature X-ray diffraction and Raman spectroscopy results reveal that (1−x)BaTiO3‒xBiYO3 ceramics undergo phase transition from tetragonal to pseudo-cubic structure with x increasing. The curves of dielectric constant and loss tangent as a function of temperature and frequency show that the dielectric constant was changing from being dependent on temperature to being independent of it upon increasing BiYO3 amount, which is induced obvious dielectric relaxation behavior. Slimmer polarization–electric field (P–E) loops and lower remnant polarization (Pr) were observed for samples with x ≥ 0.08. The transition between the ferroelectric and relaxor states leads to the narrow strain–electric field (S–E) loops, which exhibit a high electric field-induced strain of 0.192% and an ultra-low strain hysteresis of 10.4% at an electric field of 70 kV/cm for x = 0.04. This excellent performance indicates that 0.96BaTiO3‒0.04BiYO3 ceramics may be promising lead-free material for high-precision displacement actuators applications.