Kinetic of crystallization and electrical conductance of Ge5As38Te57 amorphous chalcogenide alloy

DTA measurements were made on Ge5As38Te57 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 Ge5As38Te57 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 As2Te3 were nucleated and grown. The activation energy of conduction as well as the disordered energy were also calculated. (C) 1999 Published by Elsevier Science B.V. All rights reserved.