Critical rate of cooling glassy melts under conditions of continuous nucleation. The application to some chalcogenide glasses

Abstract

The aim of this work is to derive a more exact expression for the critical cooling rate and to verify it experimentally on the systems As 2Se3, AsSeI, Cu5[As2Se 3]95, Cu15[As2Se3]85, and Cu15[AsSe1.4I0.2]85. We assume that in addition to the growth of the nuclei, one should take into account the continuous increase in their number, i.e. the occurrence of new nucleation events. The obtained equation shows the dependence of the ratio of crystalline phase volume on the critical cooling rate. In principle, this relation allows for the calculation of the cooling rate b that should be applied under the condition that the crystallization rate does not exceed a value α0, given in advance. The calculated cooling rates for the investigated systems can be considered as more exact compared to those previously reported for similar systems and are in agreement with our previous experimental findings.