Combination of Indirect and Direct Approaches to the Description of Complex Crystallization Behavior in GeSe2-rich Region of Pseudobinary GeSe2-Sb2Se3 System

Abstract

The crystallization behavior of the (GeSe2)(x)(Sb2Se3)(1-x) system for x = 0.6-0.9 was studied indirectly by using differential scanning calorimetry (DSC) under non-isothermal conditions. DSC experiments revealed a complex behavior consisting of several subprocesses. Using the direct observation method of infrared microscopy and X-ray diffractometry, we found that the overall complicated crystallization process occurred via nucleation and growth of two different crystalline phases, Sb2Se3 and GeSe2. The overall crystallization behavior was analyzed within the current kinetic theory. The deconvoluted DSC curves were fitted using a combination of Gaussian, Johnson-Mehl-Avrami, and autocatalytical models to describe the kinetics of the subprocesses. The combination of the different kinetic models provided reliable kinetic parameters which corresponded well with the direct observation of the crystal growth process followed by microscopy.