Acoustic emission and dielectric studies of phase transitions within the morphotropic phase boundary of xPb(Zr1/2Ti1/2)O3-(1−x)Pb(Ni1/3Nb2/3)O3 relaxor ferroelectrics

摘要

We have carried out a combined acoustic emission(AE) and dielectricpermittivity study of the xPb(Zr1/2Ti1/2)O3-(1−x)Pb(Ni1/3Nb2/3)O3relaxor ferroelectric ceramics with compositions x=0.7–0.9 corresponding to its morphotropic phase boundary. Temperatures of all phase transitions occurring on heating are identified accurately by AE, and a direct transition between the low-temperature (rhombohedral) and high-temperature (pseudocubic) relaxor phases is found. The AE peak intensity is generally proportional to the temperature derivative of the dielectricpermittivity, in agreement with a model proposed for a thermally cycled small elastic dipole.