Surface Induced Devitrification of Glasses: The Influence of Elastic Strains

摘要

It is shown that the account of elastic strains evolving in crystallization processes of glasses may be of significant importance for the understanding of the often observed preferential surface devitrification of a variety of vitreous materials. According to the discussed here mechanism the only parameter of the considered system determining the preference to surface crystallization is the misfit parameter δ. δ is a. measure of the relative change of the volume of the glass in crystallization. In agreement with experimental results it is found that preferential surface crystallization has to be expected to occur for systems with large values of the misfit parameter δ. Moreover, in comparison with planar interfaces, the inhibiting effect of elastic strains on crystallization is even more decreased for glass powders and rough surface structures of the glass samples. In this way, powders of glass, edges, corners etc. on the glass surface may serve as centers for crystallization.