Kinetic of crystallization and electrical conductance of Ge 5As 38Te 57 amorphous chalcogenide alloy

Abstract

DTA measurements were made on Ge 5As 38Te 57 amorphous chalcogenide alloy. The glass transition temperature ( T g), the first exothermic peak ( T c1) and the second exothermic peak ( T c2) were found to increase as the heating rate increases. The kinetic parameters were evaluated from the DTA curves and related to the crystallization mechanism where both the bulk and surface cyrstallization were considered. The crystal nucleation and growth of Ge 5As 38Te 57 glass were studied by three simple methods, and the average activation energy of nucleation was found to be 31.74 kcal/mol. The apparent activation energies for crystallization were estimated to be 59.7 and 42.6 kcal/mol for the 1st and 2nd peak, respectively. X-ray analysis for samples, isothermally annealed at temperatures higher than the glass transition and crystallization temperatures indicates that phases of Te and As 2Te 3 were nucleated and grown. The activation energy of conduction as well as the disordered enegy were also calculated.