Kinetic analysis of the crystallization processes in the glasses of the Bi-As-S system

Kinetic analysis of the crystallization process in Bi-4(As2S3)(96) and Bi-6(As2S3)(94) glasses was performed based on DSC curves recorded under non-isothermal measurement conditions. Samples were thermally treated at different heating rates in the temperature range 300-770 K. The activation energy of crystallization E and the pre-exponential factor K (0) are determined by the Kissinger method and the characteristic crystallization parameters m and n of investigated glasses by the Matusita method. For both crystallization processes the glass with 4 at.% of Bi is characterized by the mechanism of volume nucleation, which is manifested in the form of two-dimensional growth at the first crystallization process, and as three-dimensional at the second one. On the other hand, in the sample with 6 at.% Bi, the average value of the parameter m is close to one, which indicates one-dimensional crystal growth. Compatibility of the values of the parameters m and n suggests that this sample has a large number of crystallization centers, which do not increase significantly during the thermal treatment.