A study of the glass forming ability of some alloys in the Ge-As-Te systemby differential scanning calorimetry

The glass formation and devitrification of alloys in the Ge-As-Te system we re studied by differential scanning calorimetry. A comparison of various si mple quantitative methods to assess the level of stability of the glassy ma terials in the above mentioned system is presented. All of these methods ar e based on characteristic temperatures, such as the glass transition temper ature, T-g, the temperature at which crystallization begins, T-in, the temp erature corresponding to the maximum crystallization rate, T-p, or the melt ing temperature, T-m. In this work the parameter K-r(T) is added to the sta bility criteria. The stability of some ternary compounds of the Ge-x As0.2y Te0.8-(x+y) type has been evaluated experimentally and correlated with th e activation energies of crystallization by the kinetic K-r (T) criterion a nd compared with those evaluated by other criteria. (C) 1999 Elsevier Scien ce S.A. All rights reserved.