Properties, stability and aging in (Pb,Sr)TiO3-PbZrO3-Pb(Mg1/3Sb2/3)O3 ferroelectric ceramics

The variation with temperature of the dielectric and piezoelectric properties and dielectric properties aging of ferroelectric ceramics with composition Pb0.95Sr0.05Mg0.042Sb0.083Ti0.45Zr0.425O3 are presented. Dielectric measurements evidenced a double relaxor system, characterized by very broad dielectric maximum at T-m = 190'C (at 200 Hz) which shifted to 195 degrees C at 200 kHz. This frequency dispersion is due to the partial relaxor characteristics of the material. A second anomaly appears as a shoulder at about 200 degrees C in the imaginary part of the dielectric constant, both on heating and cooling curves. This could be attributed to the presence of a secondary relaxor system. The aging of dielectric properties has been investigated at different quenching temperatures below T-m. Aging and rejuvenation are found to be of relaxor type. This is rather surprising since the amount of relaxor phase content is relatively small. Properties variation with temperature has been measured up to 140 degrees C. It has been found that the elastic and piezoelectric constants show only a small variation for temperatures up to 90 degrees C.