Degradation of Piezoelectric Properties at Resonant Operational Mode by a Large Input Power

Piezoelectric properties at resonant operational mode were measured after applying a large input power and are discussed from the viewpoint of heat generation. The heat generation by a large input power was yielded from both mechanical vibration and dielectric losses. Below 50° C, mechanical vibration and dielectric losses were larger in low-Q m than high-Q m materials; therefore heat generation became larger in low-Q m material. The pulsed input power could suppress the heat generation, resulting in the decrease of degradation in piezoelectric properties.