Cryogenic temperature characteristics of Verdet constant of terbium sesquioxide ceramics

Abstract

The dependence of the Verdet constant on temperature in the (80–300 К) range for a promising magneto-active material terbium sesquioxide Tb2O3 at the wavelengths of 405–1064 nm is considered. For each of the studied wavelengths, the Verdet constant of the material cooled down to the liquid nitrogen temperature increased by more than a factor of 3.2 as compared to the room temperature value. Similarly to the other paramagnetics, the increase follows the law ∼1/T. Approximations for the temperature dependence of the Verdet constant have been obtained and the value of 1/V·(dV/dT) has been estimated. This information is needed to determine the angle of rotation as well as the variation of the extinction ratio of a Faraday isolator with temperature and extremely important at creation a cryogenic Faraday devices.