Temperature dependence of frequency and dielectric constants of pure and doped PBSZT ceramics in the morphotropic phase boundary

The variation of the resonant and anti-resonant frequencies of the longitudinal mode of particular doped PBSZT ceramics versus thermal cycle (+5/spl deg/C-+140/spl deg/C) is studied. A substantial thermal hysteresis of the frequencies may be observed during the first heating/cooling process for precise compositions. The study of the temperature dependence of some electromechanical coefficients has been performed to evaluate a possible influence of the frequencies change. The above mentioned hysteresis has been interpreted in terms of stabilization of ferroelectric domain configuration, widely damaged when oxygen vacancies exist in the ceramic.