Combined Piezoelectrooptic Effect in Rochelle Salt at the Phase Transition

TL;DR

This study investigates the combined piezoelectrooptic effect in Rochelle salt crystals during phase transition, revealing temperature-dependent behavior and confirming theoretical predictions about coefficient equality and polarization influence.

Contribution

It provides experimental validation of the combined PEO effect in Rochelle salt and explains the phase transition behavior through polarization-induced effects.

Findings

Coefficients of combined effect are equal, matching theory.

Anomalous temperature dependence linked to dielectric permittivity.

Piezooptic changes explained by linear and quadratic PEO effects.

Abstract

The results of study of piezoelectrooptic (PEO) effect in the course of ferroelectric-ferroelastic phase transition in Rochelle salt crystals are presented. The coefficient of the combined effect is obtained from measurements of the changes in the electrooptic coefficients under the action of mechanical stress and the changes in the piezooptic coefficients under the action of electric field (or spontaneous polarization). It is shown experimentally that the values of both coefficients are the same, as predicted by the theory. The temperature dependence of the coefficient of combined PEO effect is obtained. Its anomalous behaviour at the phase transition appears due to the dielectric permitivity anomaly. It is also demonstrated that the change in the piezooptic coefficients at the phase transition in Rochelle salt crystals may be satisfactorily explained as a result of linear and quadratic PEO effect induced by spontaneous polarization.