Structural phase transition behaviour and electrical properties of Pb(Mg1/3Nb2/3)O3–PbTiO3–PbZrO3 ceramics

Abstract

Piezoelectric ceramics with compositions of (1 − x − y)Pb(Mg1/3Nb2/3)O3–yPbTiO3–xPbZrO3 (PMN–PT–PZ), x = 0.025, 0.05, 0.075 and 0.1, close to the morphotropic phase boundary (MPB) were systematically investigated as a function of PT content (y). With increasing PT content, the structures of ceramics in every fixed PZ content series experience a gradual transition process from the rhombohedral to the tetragonal phase near the MPB. Electrical properties such as piezoelectric coefficient (d33), electromechanical factor (kp), remnant polarization (Pr) and dielectric constant (εr) in the respective series all exhibit the peak values corresponding to the structural phase transition near the MPB. Investigations on the temperature dependence of the dielectric constant of (0.95−y)PMN–yPT–0.05PZ ceramics show that an increased Curie temperature Tc and rhombohedral/tetragonal phase transition temperature TR–T, as well as relatively high electrical properties, can be obtained in some selected compositions. This indicates that the ternary system deserves further exploration for high-temperature applications, especially for the hot research on promising candidates for high-temperature relaxor-based ferroelectric single crystals.