Linear magnetic birefringence measurements of Faraday materials.

Abstract

Measured values of the linear magnetic birefringence (Cotton-Mouton) coefficients of several Faraday-active materials (${\mathrm{Tb}}^{3+}$, ${\mathrm{Ce}}^{3+}$, and ${\mathrm{Pr}}^{3+}$ rare-earth composites) are presented. These coefficients are compared with the same coefficients measured for diamagnetic materials: ZnSe, and the liquid solvents benzene, chloroform, acetone, and water. Relatively large Cotton-Mouton coefficients, which have a strong dependence on the paramagnetic susceptibility and concentration of rare-earth ions present in these materials, have been observed for the paramagnetic Faraday materials. Difficulties introduced into the measurement of small Cotton-Mouton effects by misalignment and/or an inherent linear birefringence of a crystalline sample are discussed.