Pressure effect on Tg for the As40Se30Te30 glass

Abstract

The variation of the glass transition temperature (Tg) with pressure has not been studied for many glasses. Such data are important in distinguishing between the 'Iso-entropy' or 'Iso-free volume' model for the glass transition. In this direction we have developed a PC based Differential Thermal Analyser (DTA) which can be adapted to high pressure cells generally used in piston-cylinder apparatus. The salient features of this system are software control of temperature with selectable heating rate, real-time digital signal filtering and plotting of DTA signal as a function of temperature. This system facilitates measurement of DTA signal in the pressure range 0 to 30 kbar and temperature range 25 to 1000°C. In this paper we present preliminary data on the pressure variation of Tg of a standard switching glass As40 Se30 Te30