Magneto-optical Faraday rotation, optical absorption and magnetization of oxide glasses with high concentration of rare earth (RE) ion additions (up to 25 mol % of R₂O₃) are investigated. Glasses had good transparence and high value of Verdet (V) constant simultaneously. So, they can be considered as a material with high magneto-optical quality. Several examples of the V spectral dependences are shown in Figs. 1-3: for Pr(III), Eu(II) and Dy(III) additions in glass matrices LiB₃O₅, SrB₄O₇, and SiO₂-P₂O₅-GeO₂, correspondingly. It is seen the different RE additions allow to obtain the V maximum at different wavelengths (_m). Magneto-optical figures of merit at several are: ~2.8*10^-1 minˇOe^-1 (248 nm) for Pr glass, ~ 5.4´10^-3 minˇOe^-1 (424 nm) for Eu glass, and ~ 5.0´10^-2 minˇOe^-1 (255 nm) for Dy glass. Note that the SrB₄O₇ glass matrix activated by Eu(II) was created purposely that allowed us to obtain for the first time Eu(II) containing material transparent in UV region.

Magneto-static measurements revealed deviations of the magnetization temperature dependence from the Curie-Weiss law at low temperatures (Fig. 4). These deviations can be due to different reasons one of which is the formation of the antiferromagnetic RE clusters. But at room temperature V is proportional to the external magnetic field up to ~10 kOe.

This work has been supported by the Russian Foundation for Basic Research (Grant No. 02-02-16428).