Electric-field-induced dielectric anomalies and optical birefringence in Pb(Mg1/3Nb2/3)1-xTixO3 (x=0.10) single crystal

Abstract

This work aims to study thermal stability, frequency response, and refractive indices in a (001)-cut Pb(Zn1∕3Nb2∕3)0.90Ti0.10O3 (PZNT10%) crystal before and after an electric (E)-field poling, which are important for piezoelectric and optical uses. Dielectric permittivities have been measured as functions of temperature, frequency, and poling strength. The dielectric absorption reveals a broad dipolar relaxation in the region of 260–310K in the unpoled sample. Piezoelectric resonances were observed in the poled sample and show significant changes while phase transitions are taking place. The unpoled crystal shows almost no birefringence, indicating that the structure averaged over the optically anisotropic ferroelectric domains is optically isotropic. Birefringence appears after an E-field poling and shows a “negative” uniaxial distortion. The Cauchy equations for ordinary no and extraordinary nerefractive indices were determined between 0.45 and 1.4μm. However, the phase-matching criterion for second harmonic generation was not found.