We have carried out a combined acoustic emission (AE) and dielectric permittivity study of the xPb (Zr1/2 Ti1/2) O3 - (1-x) Pb (Ni1/3 Nb2/3) O3 relaxor 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 dielectric permittivity, in agreement with a model proposed for a thermally cycled small elastic dipole.
Bibliographical noteFunding Information:
This work was supported by the U.S.-Israel Binational Science Foundation through Grant No. 2006235.