Structural phase transition behaviour and electrical properties of Pb(Mg1/3Nb2/3)O3–PbTiO3–PbZrO3ceramics

Piezoelectric ceramics with compositions of (1 − x − y )Pb(Mg 1/3 Nb 2/3 )O 3 – y PbTiO 3 – x PbZrO 3 (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 ( d 33 ), electromechanical factor ( k p ), remnant polarization ( P r ) and dielectric constant (ε r ) 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– y PT–0.05PZ ceramics show that an increased Curie temperature T c and rhombohedral/tetragonal phase transition temperature T R–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.