Abstract
The kinetics of crystallization of Pb15Ge27Se58 was studied by differential scanning calorimetry non-isothermally. Various experimental methods are currently employed for determining the kinetic parameters of crystallization in a glassy system. These parameters include the activation energy of crystallization E (kJ/mol), the kinetic exponent n and the frequency factor K-o (s(-1)). Recently, a new method (VHR method) has been derived from Johnson-Mehl-Avrami (JMA) transformation rate equation to calculate - in sequence - the crystallization kinetic parameters of a glassy system. The VHR technique has been used to estimate the crystallization parameters of Pb15Ge27Se58 chalcogenide glass under non-isothermal conditions. The average value of E, n and K-o are found equal to 181.74 +/- 0.58 (kJ/mol), 1.085 +/- 0.023 and (9.196 +/- 0.716) x 10(12) (s(-1)), respectively. The kinetic exponent, n approximate to 1 indicates a surface nucleation mechanism. (C) 2009 Elsevier B.V. All rights reserved.