Effect of wide range of heating rate on the crystallization kinetic parameters of Se77Te20Sb3 glass

Determination of the crystallization kinetic parameters of Ge22.5Te77.5 glass using model-free and model-fitting methods

“…KAS, Tang, Starink and Vyazovkin methods give similar values of E˛, while FWO method gives values of E˛lower than the values obtained by the other isoconversional methods by maximum difference of 1.13%. This close agreement between KAS, Tang, Starink and Vyazovkin isoconversional methods was also reported by many authors [18,20,23,[58][59][60][61]. It is evident from the observed temperature dependence of the activation energy in the present glass that the amorphous to crystalline transformation cannot be described by a single-step mechanism.…”

“…For non-isothermal experiments, model-fitting involves fitting different models to (˛− T) curves and simultaneously determining E and A [18][19][20]. One of these models proposed by Kennedy-Clark method [55], which is given by the following expression:…”

“…Plotting ln[ˇg(˛)/(T − T 0 )] versus 1/T gives a straight line of slope (−E/R) and the intercept ln A for different reaction models of g(˛). The most common reaction models used to describe solid-state reactions are listed in the previous work [20]. The other popular model is Coats-Redfern method [56,57], which is given by the following expression:…”

“…The activation energy of the glass crystallization is associated with nucleation and growth processes. Studies of the crystallization of a glass upon heating can be performed in several different ways and the crystallization process can be interpreted in terms of several theoretical models [17][18][19][20][21].…”

“…The main objective of the kinetic analysis of crystallization process is to determine the kinetic parameters such as activation energy, E, pre-exponential factor, A, and reaction model, g(˛) [18][19][20]22]. Information about this kinetic triplet (E˛, A˛, and f(˛) or g(˛),˛being the extent of conversion) can be used to identify the crystallization process mechanism(s).…”