Thermal Behaviour of Zr65Cu17.5Ni10Al7.5 Glassy Alloy

Abstract

Abstract Estimating entropy of glass cannot be performed using the time-dependent and irreversible part of the heat capacity (Cp ) which is measured in the glass-formation range. The difference of the estimate and the real change in entropy can be determined by calculating the change in the CpdT and CpdlnT integrals before and after isothermal annealing by using DSC. In this paper, we report this estimation difference for Zr65Cu17.5Ni10Al7.5 glassy alloy. The minimized annealing results in the CpdlnT integrals for the cooling and the heating paths approach the same value. We affirm that entropy is an ensemble-averaged value since the Clausius limits show that the estimation of the residual entropy is not affected significantly by irreversibility and its value can be estimated from the Cp data.