Two heating rates as a method for calculating the kinetic parameters of crystallization in a glassy system

Abstract

Various experimental methods are currently employed for determining the kinetic parameters of crystallization in a glassy system. These parameters include the activation energy E (kJ/mol), the Avrami exponent or the reaction order (n) and the frequency factor K 0 (s -1 ). In the present work, a new method is derived from Johnson -Mehl -Avrami (JMA) equation to calculate the kinetic parameters of crystallization. The method starts with determining the activation energy E. The method depends on obtaining the same volume fraction of crystallization x(t) at two heating rates. Next, the reaction order n and the frequency factor K 0 are determined successively. The present method is straightforward and involves no assumptions in addition to those involved in obtaining JMA equation. The new technique has successfully predicted the crystallization parameters of Ge 10 Te 35 As 55 glasses during non-isothermal annealing.

Crystallization kinetics determination of Pb15Ge27Se58 chalcogenide glass by using the various heating rates (VHR) method

“…Also, most of these methods and techniques determine the kinetics parameters of crystallization reaction from data based on the maximum Since these methods use only one experimental point from each of the curves obtained for each heating rate, other methods are proposed as an alternative, as it makes it possible to use a large number of values obtained from the entire experimental curve for each of the different heating rates. These methods are widely used in the literature, with varying results depending on the nature of the glassy alloys to which they are applied [18,19,[29][30][31][32][33].…”

“…The study of crystallization kinetics, based on the so called Johnson-Mehl-Avrami (JMA) theoretical model, in glass systems by differential scanning calorimetry (DSC) method has been widely discussed in the literature [17,[23][24][25][26][27][28][29][30][31]. However, most of these methods used certain approximations, which in turn limit the accuracy of the resultant parameters [17,23,25,27,31].…”

“…However, most of these methods used certain approximations, which in turn limit the accuracy of the resultant parameters [17,23,25,27,31]. Also, most of these methods and techniques determine the kinetics parameters of crystallization reaction from data based on the maximum Since these methods use only one experimental point from each of the curves obtained for each heating rate, other methods are proposed as an alternative, as it makes it possible to use a large number of values obtained from the entire experimental curve for each of the different heating rates.…”

Various heating rates (VHR) as a method for crystallization kinetics determination and its application to Se75.5Te20Sb4.5 chalcogenide glass

“…However, most of them used certain approximations, which in turn limit the accuracy of the resultant parameters [1,2,11,14,16,24]. Also, most of these methods and techniques determine the kinetics parameters of crystallization reaction from data based on the maximum value of the DSC curve.…”

“…Since these methods use only one experimental point from each of the curves obtained for each heating rate, other methods are proposed as an alternative, as it makes it possible to use a large number of values obtained from the entire experimental curve for each of the different heating rates. These methods are widely used in the literature, with varying results depending on the nature of the glassy alloys to which they are applied [4,5,20,21,[24][25][26][27].…”