The structure and devitrification behaviour of barium borotitanate glasses examined by Fourier transform infrared spectroscopy, differential thermal analysis and x-ray diffraction, are reported. Glass compositions are expressed by the formula: (50-x/2)BaO.(50-x/2)B2O3.xTiO(2) with x=4, 8 and 16. Titanium acting as glassformer gives a more polymerised structure increasing the glass stability with respect to devitrification. The nonisothermal devitrification of the studied glasses occurs in one or two steps depending on the TiO2 content in the glass composition and the specific surface area of the sample. The surface crystallisation was found to be dominant for all glasses. The investigated glasses devitrify forming beta-BaB2O4 microcrystals as the main crystalline phase.
Structure and nonisothermal crystallisation of glasses in the BaO-B2O3-TiO2 system / Pernice, P., S., E., Aronne, A.. - In: PHYSICS AND CHEMISTRY OF GLASSES. - ISSN 0031-9090. - STAMPA. - 39:(1998), pp. 222-227.
Structure and nonisothermal crystallisation of glasses in the BaO-B2O3-TiO2 system
PERNICE, PASQUALE;ARONNE, ANTONIO
1998
Abstract
The structure and devitrification behaviour of barium borotitanate glasses examined by Fourier transform infrared spectroscopy, differential thermal analysis and x-ray diffraction, are reported. Glass compositions are expressed by the formula: (50-x/2)BaO.(50-x/2)B2O3.xTiO(2) with x=4, 8 and 16. Titanium acting as glassformer gives a more polymerised structure increasing the glass stability with respect to devitrification. The nonisothermal devitrification of the studied glasses occurs in one or two steps depending on the TiO2 content in the glass composition and the specific surface area of the sample. The surface crystallisation was found to be dominant for all glasses. The investigated glasses devitrify forming beta-BaB2O4 microcrystals as the main crystalline phase.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
