Structural phase-transition region and electrical properties of Pb(Ni1∕3Nb2∕3)O3–Pb(Zn1∕3Nb2∕3)O3–PbTiO3 ceramics

Abstract

The phase structures, and dielectric and piezoelectric properties of three series of ceramic compositions in the Pb(Ni1∕3Nb2∕3)O3–Pb(Zn1∕3Nb2∕3)O3–PbTiO3 ternary system have been systematically investigated. The existence of the morphotropic phase boundary (MPB) line is proposed and a wide linear MPB region is verified. The contents of the coexisting rhombohedral and tetragonal phases vary irregularly along the MPB line, while the sole increase of PT with a fixed ratio of Ni∕Zn leads to the decrease of the rhombohedral phase in the MPB region. Compositions on the Ni-rich side of the MPB line show better electrical properties than those on the Zn-rich side. The MPB composition of 0.56Pb(Ni1∕3Nb2∕3)O3–0.14Pb(Zn1∕3Nb2∕3)O3–0.30PbTiO3 was found to be with high values of εm and d33(εm=24500 and d33=740pC∕N), which is superior to those of many reported ferroelectric ceramics.