Phase transitions in the Pb (Zn1/3Nb2/3)O3-PbTiO3system

Abstract

Two successive phase transitions, changing the crystal symmetry from rhombohedral to tetragonal, and then to cubic on a heating process, have been investigated in the Pb(Zn_1/3Nb_2/3)O₃-PbTiO₃ single crystals with the composition near the morphotropic phase boundary. The existence of the morphotropic phase boundary has been confirmed by measuring the dielectric, piezoelectric and pyroelectric constant. Anomalously large electromechanical and piezoelectric constants are observed on the morphotropic phase boundary.