New stable fluoroindate glasses

Potential applications of fluoride glasses are centered upon passive and active optical fibers. In various cases, phonon energy is a sensitive factor for the efficiency of the optical components. Because of their lower phonon energy, fluoroindate glasses offer some advantages over fluorozirconate glasses. However, the fiber-drawing ability and the resistance against devitrification are higher in InF3-based glasses. New compositions have been investigated in order to extend IR transmission and enhance thermal stability. Various compositions are reported in the multicomponent system containing In. Ga, Y, Zn, Sr, Ba and Na. A typical composition is 30% InF3-10% YF3-25% BaF2-5% SrF2-10% NaF-10% ZnF2-10% GaF3. This InYBSNZnGa glass has a good stability exemplified by the value of the stability factors: T-x - T-g = 108 K, S = 4.1 K. Glass transition temperature, T-g = 309 degreesC. Thermal, optical and physical properties of these glasses are reported and the effects of materials purity and processing on these properties are discussed. These glasses corrode less in aqueous solutions than other fluoride glasses. (C) 2001 Elsevier Science B.V. All rights reserved.