Analysis of the crystallization kinetics in the semiconducting glassy alloy Cu_(0.20)As_(0.35)Te_(0.45)

摘要

A study of the crystallization kinetics of the glassy alloy Cu_(0.20)As_(0.35)Te_(0.45) was made using a method in which the crystallization rate is deduced bearing in mind the dependence of the reaction rate constant on time, through temperature. The method was applied to the experimental data obtained by differential scanning calorimetry, using continuous heating techniques. The alloy studied exhibited overlapping exothermic peaks, which were resolved using a numerical method developed by the authors, making it possible to study the crystallization phases separately. The kinetic parameters determined for each stage have made it possible to discuss the different types of nucleation and crystal growth exhibited by each stage of the crystallization process. The phases at which the alloy crystallizes after the thermal process have been identified by X-ray diffraction. In both stages of the process, microcrystallites of As_2Te_3 and Cu_7Te_5 are crystallized in an amorphous matrix. In the second stage, a small amount of the crystalline phase CuTe appears, coexisting with the aforementioned crystalline compounds.