Shift of morphotropic phase boundary in high-performance fine-grained PZN-PZT ceramics

The fine-grained xPb(Zn1/3Nb2/3)O-3-(1 - x)Pb(Zr0.47Ti0.53)O-3 system has been prepared from submicron precursor powders obtained by highenergy ball milling method. The addition of PZN induces a decrease of grain size from an initial micron scale to a submicron scale, accompanying with the phase transition from tetragonal to morphotropic phase boundary (MPB), and then rhombohedral side. Interestingly, compared to the former published data for coarse-grained ceramic, the MPB has shifted from 50% to 30% PZN content side due to the enhancement of the internal stress for fine-grained ceramic. The enhanced electrical and mechanical performances are closely associated with the phase structure and grain size. A high piezoelectric property (d(33) = 380 pC/N and k(p) = 0.49) as well as mechanical performance (H-v = 5.0 GPa and K-IC = 1.33 MPam(1/2)) were obtained simultaneously for the MPB 0.3PZN-0.7PZT ceramics with an average grain size of 0.65 mu m. (C) 2014 Elsevier Ltd. All rights reserved.