Electrically and magnetically induced optical rotation in Pb5Ge3O11:Cr crystals at the phase transition. 2. Faraday effect in pure and Cr-doped lead germanate in the presence of electric field and spontaneous polarization

TL;DR

This study investigates the Faraday rotation in pure and Cr-doped lead germanate crystals during phase transition, revealing a magneto-electrooptic effect linked to spontaneous polarization that enhances optical rotation.

Contribution

It demonstrates the combined magneto-electrooptic effect in lead germanate crystals and its dependence on spontaneous polarization during phase transition.

Findings

Faraday rotation increases at the phase transition

The effect is proportional to the square of spontaneous polarization

Combined magneto-electrooptic effects are observed

Abstract

This work presents the results for the Faraday rotation in pure and Cr-doped lead germanate crystals studied in the course of proper ferroelectric phase transition. We show that the increment of the Faraday rotation appearing at the phase transition is caused by a combined magneto-electrooptic effect induced by spontaneous polarization. It is proportional to the square of spontaneous polarization. The phenomenon revealed by us corresponds to combined effects of crystal optics, which appear due to common action of different fields.