Non-isothermal devitrification of strontium germanate glasses

The devitrification behavior of strontium germanate glasses; examined by di fferential thermal analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), is reported. The glass compositions are expre ssed by the general formula: xSrO(1-x)GeO2 with x = 0.050, 0.125, 0.200 and 0.250. The glasses with x = 0.050 and 0.125 exhibit two glass transition t emperatures due to a phase separation. The phases crystallizing during DTA runs were identified and devitrification mechanisms proposed. In all glasse s SrGe4O9 crystals grow from bulk nuclei. The effect on devitrification pro cesses of the specific surface area of the samples was also pointed out. (C ) 1999 Elsevier Science S.A. All rights reserved.