THERMODYNAMIC AND THERMOKINETIC CHARACTERISTICS OF THE GLASS-TRANSITION IN A GESE2-GETE-SB2TE3 ALLOY

Glassy alloys of (GeSe//2)//7//0 (GeTe)//1//5 (Sb//2Te//3)//1//5 were prepared by water-quenching and subjected to several thermal treatments through the glass transition region. The thermodynamic and thermokinetic characteristics of the glass were inferred from heat capacity measurements by differential scanning calorimetry. It was demonstrated that the undercooled liquid obtained by heating the glass is in equilibrium, and what is more, that not only each particular cooling process through the glass transition produces a given glass, but also that any trace of that glass may be suppressed by reheating above glass transition. The enthalpy and entropy differences between each glass and the undercooled liquid used to obtain that particular glass were taken as properties sensitive to the relaxation inherent to the formation of the glass. The activation energy spectrum characterizing the relaxation processes on cooling through the glass transition has been obtained.