Crystallization kinetics and network rigidity

Abstract

Kinetics of crystal growth in non-isochemical systems is considered taking into account thechanges in composition of the residual melt during the process. This leads to theformation of concentration gradients in the vicinity of the new phase. If a componentacting as a network modifier is enriched in the crystalline phase, the melt at theinterface is enriched in network formers and the glass network will turn fromfloppy to rigid. Consequently, the crystal grows until a critical concentration isreached, at which the melt locally turns to a rigid one. There is a critical size of thecrystal, above which the growth rate strongly decreases because the network formerconcentration at the interface drops below the threshold limit. The problem issolved numerically and finite differences are used for space and time discretization.