Study of the kinetics of non-isothermal crystallization in Ge 20Te 80 chalcogenide glass

Abstract

Differential scanning calorimetry (DSC) data at different heating rates (5⩽α⩽50 K/ min) of Ge 20Te 80 chalcogenide glass are reported and discussed. From the heating rate dependences of the glass transition temperature ( T g), the onset temperature ( T 0) and the crystallization peak temperature ( T p), the activation energy for glass transition, E g, and the activation energy for crystallization, E c, were derived. The crystallization data are interpreted in terms of recent analyses developed for non-isothermal conditions. The obtained value of the Avrami index ( n=2.0±0.1) indicates that one crystallization mechanism, two-dimensional growth, is responsible for the amorphous–crystalline transformation. The calculated E g and E c are 134.1±3.5 and 184.3±3.5 kJ/mol , respectively.