A kinetic study on non-isothermal crystallization of the glassy alloy Sb0.16As0.43Se0.41

A procedure has been used for analyzing the evolution with time of the volume fraction crystallized and for calculating the kinetic parameters at non-isothermal reactions in materials involving formation and growth of nuclei. Considering the assumptions of extended volume and random nucleation, a general expression of the fraction crystallized has been obtained as a function of the temperature for interior crystallization. The kinetic parameters have been deduced, assuming that the crystal growth rate has an Arrhenius-type temperature dependence, and the nucleation frequency is either constant or negligible. The theoretical method described has been applied to the crystallization kinetics of glassy alloy Sb0.16As0.43Se0.41 with and without previous reheating. According to the study carried out, the values of the kinetic exponent, n, are 1.8 for the as-quenched glass and 0.9 for the reheated glass. As n decreases with reheating, it is possible to state that the annealing causes the appearance of new nuclei. The phases at which the alloy crystallizes after the thermal process have been identified by X-ray diffraction. Based on the diffractogram of the transformed material we suggest the presence of microcrystallites of Sb2Se3 and AsSe, remaining in the amorphous matrix.