The combined analysis of the DSC curves recorded under different heating rates for the crystallization of (GeS2)0:3(Sb2S3)0:7glass allows one to conclude that the reaction rate of this process follows an Avrami–Erofeev mechanism with values of the activation energy and the preexponen tial factor of Arrhenius that remain constant all over the crystallization process. This behavior indicates that nucleation is completed in the sample before the growth process is started and, therefore, the crystallization rate of (GeS2)0:3(Sb2S3)0:7bulk glass is controlled by the growing of preexisting nuclei [35]. As mentioned above, under these conditions, the validity of the JMA kinetic model can be extended to non-isothermal conditions.