Simple rules for the prediction of the value of the glass transition temperature in network glasses
نویسندگان
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
منابع مشابه
Microstructure, mechanical and thermal properties of chalcogenide glasses and glass-ceramics based on Se-As-Ge system nucleated by Sn
In particular, chalcogenide glasses and glass-ceramics are new materials that exhibit good transparency in infrared region (0.8-12µm). We can overcome the main weakness of these glasses by improving the hardness through controlling crystallization. In this paper, we report results of a study on chalcogenide glasses in the ternary system of As-Se-Ge with nominal composition of Snx (Se...
متن کاملA NEW GENERATION OF OXYNITRIDE GLASSES CONTAINING FLUORINE
Oxynitride glasses are found as grain boundary phases in silicon nitride ceramics. They are effectively alumino-silicate glasses in which nitrogen substitutes for oxygen in the glass network, and this causes increases in glass transition and softening temperatures, viscosities (by two to three orders of magnitude), elastic moduli and microhardness. Calcium silicate-based glasses containing fluo...
متن کاملStructural Investigation, Physical and Optical Properties of Mixed Alkali Bismuth Borate Glasses
Lead free, eco-friendly bismuth borate glasses doped with alkali oxides of composition xLi2O+(30-x)Na2O+55B2O3+15Bi2O3 (x = 5,10,15,20,25) were prepared by melt quenching technique. Amorphous nature of glasses was confirmed by X-ray diffraction. Density measurements were carried out at room temperature by standard principle of Archimedes with Xylene as an immersion liquid. The non-linear ...
متن کاملDetermination of the activation energy of crystallization based up on Ozawa and Kissinger formalisms and thermal stability of V2O5-NiO- TeO2 glasses by differential scanning calorimetry (DSC)
In the present research work, (60-x)V2O5-xNiO-40TeO2 amorphous bulk compositions with different molar percentages of 0≤x≤20 mol%, were prepared by well-known rapid melt-quenching method. Differential scanning calorimetry (DSC) at different heating rates (φ) was used to thermal analyze and to obtain more insight in to the thermal stability, glass forming tendency and so calorimetric characteris...
متن کاملCOMPARISON OF DIFFERENT GLASS COMPOUNDS FOR INTRINSIC FIBER OPTIC TEMPERATURE SENSORS
Different glasses suitable for temperature sensing in the fiber optic sensors were studied in this article. The phase changes for eight different glass materials were calculated and results were compared. Our results showed that extra dense flint glass is the most sensitive one, while pure silica results in the lowest phase change. In another study the effect of wavelength on the phase variatio...
متن کامل