Phase stability, dielectric and piezoelectric properties of relaxor based ferroelectrics

Abstract

The phase stability, dielectric and piezoelectric properties of relaxor based ferroelectrics near the morphotropic phase boundary (MPB) were investigated. Among the relaxor–PbTiO3 materials, Pb(Sc1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3—PbTiO3 (PSN–PMN–PT) ceramic material exhibits excellent piezoelectric properties near the MPB, such as kp > 70%, kt > 54%, k 33 > 77%, d 33 > 500pC/N and Tc = 160–260°C. The ceramic has superior piezoelectric properties as compared with conventional PZT ceramics, which so far have been thought to be the best binary piezoelectric ceramic materials. One of the big advantages of relaxor–PT systems compared with PZT is the case with which single crystals of the MPB composition can be grown. These single crystals generally have superior properties compared with the ceramics if appropriate axis is utilized. The advantage and disadvantage of relaxor–PT systems are compared with PZT.