Borogermanate glasses with a high terbium oxide content

• Published in: Journal of non-crystalline solids Vol. 356; no. 33; pp. 1655 - 1659
• Main Authors: Savinkov, V.I., Sigaev, V.N., Golubev, N.V., Sarkisov, P.D., Masalov, A.V., Sergeev, A.P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.07.2010
• Subjects: Borogermanate system; Glass; Homogeneity; Magnetooptics; Melting; Melts; Oxide glass; Oxides; Silicates; Spectra; Terbium; Verdet constant; Wavelengths; Oxide glass; Terbium; Magnetooptics; Borogermanate system
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2010.06.011

Glasses in Tb 2O 3–B 2O 3–GeO 2 (TBG) system with high, up to 33 mol% Tb 2O 3 content, have been obtained, and their crystallization behavior, spectral and magneto-optical properties studied. It was found that Verdet constant V of TBG glasses for wavelength 632.8 nm reached very high values: more than 0.4 arc min/cm Oe. Transparent and colorless TBG glasses with low absorption coefficient a for working wavelength 1.064 μm were prepared by varying redox conditions of melting. It provided high magneto-optical figure of merit V/ a exceeding the same option of industrial glasses. The melt temperature of TBG glasses obtained did not exceed 1450 °С. This temperature is much lower than that of silicate magneto-optical glasses, promoting homogeneity of glass melt and facilitating production of TBG optical quality glasses. The observed correlation between the Verdet constant and Tb 3+ content indicates that the Borrelli's approach, explaining magneto-optical activity in glasses only by paramagnetic ion content, extends also to high concentrated rare earth oxide glasses.