Effect of texture on temperature-dependent properties of K_0.5 Na_0.5 NbO₃ Modified Bi_1/2 Na_1/2 TiO₃-x BaTiO₃

Textured (1-x-y)Bi_1/2Na_1/2TiO₃-xBaTiO ₃-yK_0.5Na_0.5NbO₃ (BNT-100xBT-100yKNN) ceramics with a {001} pseudocubic (pc) orientation were fabricated by templated grain growth using Bi_1/2Na _1/2TiO₃ templates. Temperature-dependent electromechanical results demonstrate that the strain response of templated BNT-xBT-yKNN ceramics is stable from room temperature (RT) to 125°C. The temperature-dependent strain and polarization response are compared to randomly oriented ceramics, for BNT-100xBT-2KNN (0.05 ≤ x ≤ 0.07). Textured BNT-7BT-2KNN reached a maximum 0.47% strain response at 5 kV/mm, an almost 50% increase compared to randomly oriented BNT-7BT-2KNN. Over the temperature range RT-125°C, the strain response of templated BNT-6BT-2KNN degraded from 0.38% to 0.22% (-42.1%) compared to 0.37% to 0.18% (-51.4%) for randomly oriented ceramics. The temperature-dependent strain response suggests that templated BNT-100xBT-100yKNN ceramics are well suited for elevated temperature applications.