Thermal stability of (1-x)BiScO3-xPbTiO3 piezoelectric ceramics for high-temperature sensor applications

High-temperature piezoelectric (1-x)BiScO3-xPbTiO(3) ceramics with composition (x=0.62, 0.63, 0.64, and 0.65) near the morphotropic phase boundary were fabricated. A thermal depoling experiment was used to investigate the stability of polarization at the temperature range from 200 degrees to 460 degrees C. The results indicated that samples with rhombohedral phase began to depole when the temperature was higher than 300 degrees C, while samples with a tetragonal phase showed good resistance to thermal depoling up to 440 degrees C, close to their Curie temperature.