Effect of thermal depolarization on the poling-induced domain texture and piezoelectric properties in Mg-doped NBT-6BT

Recently, poled Na_0.50Bi_0.50TiO₃-BaTiO₃ (NBT-BT)-based polycrystalline materials have been characterized as possessing a high degree of poling-induced domain texture in their remanent state. This finding is suggested to be the reason for their stable mechanical quality factor at high-vibration velocity, making them promising candidates for high-power applications. The materials in consideration are prone to self-heating and thermal run-away, particularly at slightly elevated temperatures. Therefore, this paper evaluates the temperature dependence of the poling-induced domain texture of (Na_0.47Bi_0.47Ba_0.06)TiO₃ (NBT-6BT) doped with 0.5 mol% of Mg as compared to undoped NBT-6BT. Its influence on small-signal, large-signal, and high-power properties was investigated. To obtain a fundamental understanding of crystal structure, in-situ synchrotron measurements were conducted as function of temperature to establish a relationship between structure and piezoelectric properties of both Mg-doped and undoped NBT-6BT materials.