Glass Transition Kinetics of a-SexTe100-x Nanoparticles

Nanoparticles of a-SexTe100-x (x = 3, 6, 9, 12) have been prepared by a melt-quenching technique. The diameter of these nanoparticles varied from 100 to 200 nm. The value of glass transition temperature and the crystallization temperature increases with changes in composition and heating rate. The activation energy for structural relaxation (Delta E-t), the activation energy of crystallization (Delta E-c), the order parameter (n), the mean bond energy (< E >) and total relaxation time (tau(Tg)) have been calculated. On the basis of the calculated values, it is observed that the glass a-Se12Te88, characterized by the lowest activation energy value and highest value of total relaxation time, is the most stable glass with good glass-forming ability among all of the compositions studied. The composition dependence of the activation energy for thermal relaxation and activation energy for crystallization has been discussed in terms of the structure of Te-Se glassy system. The thermal stability of these nanoparticles has also been studied through the estimation of thermal stability parameter (S) representing resistance to devitrification and Hruby number (H-R).