Simple rules for the prediction of the value of the glass transition temperature in network glasses
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چکیده
§ Laboratoire GCR-CNRS URA 769 Université Pierre et Marie Curie, Tour 22, Boite 142 4, Place Jussieu, 75252 Paris Cedex 05, France ¶ Instituto de Fisica, Universidad Nacional Autonoma de México Apartado Postal 20-364, 01000 México DF, México (February 1, 2008) We give in this letter a set of general rules which allow the prediction of the value of the glass transition temperature Tg in network glasses. Starting form the Gibbs-Di Marzio law which gives a very general relationship between this temperature and the average coordination number of a system, we explain how to compute from the valencies of the atoms of the glass, the parameter β used in this law. We check the validity of the obtained expression and show that it is possible to predict the glass transition temperature for any composition in multicomponent chalcogenide glasses. The possibility of existence of a demixed structure is also discussed. Pacs: 61-20N, 61-80P
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تاریخ انتشار 2008