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 (P_r ) 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⁻¹ for x= 0.04. This excellent performance indicates that 0.96BaTiO₃‒0.04BiYO₃ ceramic may be promising lead-free materials for high-precision displacement actuators applications.