A Thermodynamic Approach To The Structure Of Oxide Glasses

The concepts of homogeneous and heterogeneous mixtures are combined to a new model of "clustered nanosize mixtures" and applied to glasses and glass melts. In the model, the constitutional phases of the underlying phase diagrams are adopted as components; their size is postulated to a few nm. Experimental evidence is compiled that these components reflect areas structural entities: Firstly the concentration dependence of thermodynamic activities of glass melts calculated on this basis matches well with experimental data. Secondly, the diffuse nevertheless specific X-ray diffraction patterns of solid glasses display shapes similar to a superposition of the main diffraction peaks of compounds of the said nature and size.