Dimensionality of the crystal growth, exponents of the power laws and activation energy for nucleation and growth processes in glass-crystal transformations under non-isothermal regime. Application to the crystallization of the Sb0.13As0.35Se0.52 glassy semiconductor

Abstract

A procedure has been described to establish the dimensionality of the crystal growth, to evaluate the exponents of the power laws corresponding to time-dependence both for the nucleation frequency and for the crystal growth rate and to calculate the activation energy for nucleation and growth processes. From the linear relation existing between the logarithms of the heating rate and of the temperature corresponding to the maximum crystallization rate, it is possible to deduce a linear relation between the logarithm of the quotient of the mentioned temperature at two different heating rates and the difference between the inverse of these temperatures. Known the kinetic exponent, the activation energy and the thermal process type, continuous nucleation or “site saturation”, it is determined the dimensionality from the slope of the last relation. From the dimensionality and the values of the kinetic exponent for the as-quenched and reheated material, the exponents of the power laws have been evaluated, from which, the activation energy both for nucleation and crystal growth has been calculated. This procedure has been applied to the crystallization kinetics of the Sb0.13As0.35Se0.52 glassy semiconductor. The results confirm the reliability of this procedure to analyse the non-isothermal transformation of the studied glassy alloy.