Abstract: In order to improve the ability of fluoroaluminate glass against devitrification, TeO₂ was introduced into fluoroaluminate glass with the molar composition of 10MgF₂-20CaF₂-10SrF₂-10BaF₂15YF₃35AlF₃. The influence of TeO₂ content on the glass formability of fluoroaluminate was studied by differential thermal
analysis technique. And the glass structure analysis was performed by infrared
absorption spectra and Raman scattering spectra. The results indicate that
TeO₂ can increase the crystallization onset temperature T _xof glasses, decrease melting temperature T _mof glasses and improve the ability against devitrification. The structure analysis indicates that,
with the increase of TeO₂ content, the YF₈polyhedral units decrease,
and more [FnAl--O--AlFn], [TeO₃], [TeO₂F] and [TeOF₂] units exist in the glass network with the introduction of TeO₂ which are bridged by the F^-and O^2-. With good glass forming ability, the
TeO₂ modified fluoroaluminate glass also shows high transmittance in the
region of 0.4~5μm; therefore it is a new prospective infrared optical material.

Key words: telluride-fluoroaluminate glass, thermal stability,infrared transmittance,glass structure