Differential scanning calorimeter studies on Pb modified Ge-Se-Te glasses

Bulk glasses Pb x Ge42 − xSe48Te10(0 ≤ x ≤ 15) and Pb20Ge x Se70 − xTe10(17 ≤ x ≤ 24) have been prepared by quenching the melt. The non-isothermal properties of these glasses have been determined using a Differential scanning calorimeter (DSC). The composition dependence of the glass transition temperature, crystallisation temperature, excess heat capacity at glass transition, glass forming tendency and activation energy of glass transition and crystallisation show anomalous features near the composition at which the p- to n-type transition occurs. These observations reflect the changes occurring in the chemical bonding and the nature of the glassy network in these glasses. The results have been interpreted in terms of existing models and the majority charge carrier reversal phenomenon occurring in these glasses.