Kinetics of Phase Transformation in Nanostructured Ga–Se–Te Glasses

Abstract

Bulk samples of Ga25Se(F5-x)Te(x) chalcogenides were prepared by melt quenching technique. The glassy nature of these alloys was verified by X-ray diffraction. The morphology of these as-prepared alloys was studied using field emission scanning electron microscopy. Kinetics of crystallization in these glassy alloys was studied under non-isothermal conditions at different heating rates (5, 10, 15, 20 and 25 K/min) using differential scanning calorimetry. The value of glass transition and crystallization temperature was found to be composition and heating-rate dependent. The value of order parameter indicates that the crystallization was due to volume nucleation with two dimensional growths. The activation energy of crystallization and activation energy of glass transition were determined from the heating rate dependence of glass transition and crystallization temperature. Both the activation energy for glass transition and the activation energy of crystallization were found to decrease from 130.05 to 102.99 kJ/mole and from 130.05 to 102.99 kJ/mole respectively with increasing Te content in Ga-Se system.