Processing and Electrical Properties of 0.5Pb(Yb1/2Nb1/2)O3-0.5PbTiO3 Ceramics

Pb(Yb_1/2Nb_1/2)O₃-PbTiO₃ ceramics at the morphotropic phase boundary (50:50) were sintered by conventional and reactive methods to 95% theoretical density and grain sizes <10 m. Excess PbO, added to enhance the densification, resulted in PbO-based non-ferroelectric phases that degraded the electrical properties. Volatilization of excess PbO by annealing the samples after sintering resulted in dense, perovskite samples and excellent electrical properties. The best electrical properties, obtained via reactive sintering, were a remanent polarization, P _r, of 0.36 C/m², a maximum dielectric constant of 31,000 (at the T _c = 371°C and 1 kHz), a piezoelectric charge coefficient, d ₃₃, of 508 pC/N, and an electromechanical coupling coefficient, k ₃₃, of 0.61.