Measurements of DSC isothermal crystallization kinetics in amorphous selenium bulk samples

In this research, the activation energies of crystallization of amorphous selenium (Se) were studied under isothermal conditions using a differential scanning calorimetric (DSC) technique. The activation energy for crystallization was determined to be 77 ± 6 kJ mol-1. The Avrami exponent was found to be about 2 for an annealing temperature of T ≤ 361 K, indicating two-dimensional growth. As the annealing temperature increases beyond 365 K, the Avrami exponent mostly gives values more than 2.5, indicating three-dimensional growth. The effects of annealing were revealed by studying the morphology of the samples with a scanning electron microscope (SEM).