Temperature Dependence of Electrooptic Coefficient and Spontaneous Birefringence of Ferroelectric Gadolinium Molybdate

Abstract

The temperature dependence of electrooptic coefficient z₆₃ and spontaneous birefringence Δn_xy^S is determined by static measurements on a single-domain and mono-phase region of a GMO crystal under the temperature control with the precision of ±10⁻²°C, so that the thermal hysteresis of about 0.1°C is clearly observed at the transition. Results on z₆₃ are in good agreement with those of Fousek’s dynamical measurements within experimental uncertainty. The third power of Δn_xy^S decreases linearly with increasing temperature in the neighborhood of the transition point. Temperature dependence of z₆₃ and Δn_xy^S is qualitatively explained by Aizu-Dvo\v{r}ák’s theory.