Ferroelectric and piezoelectric properties of BaTiO₃-templated 0.36BiScO₃-0.64PbTiO₃ thick films for piezoelectric device applications

A novel 0.36BiScO₃-0.64PbTiO₃ (0.36BS-0.64PT) textured ceramic was developed using plate-like BaTiO₃ (BT) templates for high temperature piezoelectric device applications. Sintering temperature and amount of BT template played important roles in improving the density, crystal orientation, and ferroelectric and piezoelectric properties of the BT-templated 0.36BS-0.64PT thick films. When sintered at 1000°C, highly dense BS-PT textured films were obtained without formation of a secondary phase. The increased amount of BT template facilitated the degree of texture but deteriorated the relative density of BS-PT thick film. In particular, enhanced ferroelectric and piezoelectric properties were obtained for 1 vol% BT-templated 0.36BS-0.64PT thick film sintered at 1000°C; this film exhibited the very large P_r (44.2 μC/cm² at 4 kV/mm), d₃₃ (444 pC/N), k_p (57.4%), and g₃₃ (36 × 10⁻³Vm/N) values. In addition, considering the inverse relation between T_C and strain, the electrostrain of d₃₃* (622 pm/V at 4 kV/mm) was excellent, showing potential for piezoelectric actuator applications.