Concentration dependences of the properties of multicomponent PZT-based piezoelectric ceramics in the morphotropic transition range

The following three ternary PZT-based systems are studied in detail: 0.98Pb(TixZr1 - x)O-3-0.02Pb(Nb1/2Bi1/2)O-3 , 0.98(Pb0.9727Sr0.0273)(TixZr1 - x)O-3-0.02Pb(Nb1/2Bi1/2)O-3 + 1 wt% PbO, and 0.98(Pb0.9727Sr0.0273)(TixZr1 - x)O-3-0.02Pb(Nb1/2Bi1/2)O-3 + 2 wt % PbGeO3, where 0.45 <= x <= 0.49 and the concentration step is Delta x = 0.025. A number of concepts are formulated regarding the phase diagrams of PZT-type systems near the morphotropic transition. A scheme for real tetragonal-rhombohedral transformation is given. The maxima of the electrophysical characteristics of the solid solutions from the morphotropic range are shown to be caused mainly by an appearing intermediate phase. Analysis of the insulating, piezoelectric, and mechanical properties of the samples demonstrates that there is a group of solid solutions that are promising materials for high-temperature piezoelectric devices operating in the medium-frequency band. (c) 2005 Pleiades Publishing, Inc.