Ceramics-Silikáty 48 (1) 1-5 (2004)

VOLUMES AND VOLUME FLUCTUATIONS OF VORONOI POLYHEDRA IN MD SIMULATED SILICATE GLASSES

O. Gedeon, M. Liška, J. Macháček

The method of Voronoi polyhedra analysis of silicate glass was suggested in terms of the averaged volumes and the volume fluctuations for each kind of the present particle; and demonstrated for 15 K₂O·85 SiO₂ glass. The thermal expansion coefficient was separated into the partial molar contributions of the individual glass components. The calculated overall value of the thermal expansion coefficient was found in a reasonable agreement with the experimental value. The relative volume fluctuation of VP was used as a sensitive indicator of the structural changes induced by the temperature increase. The different positions of the well ordered SiO₄ sub-network manifest itself in lower but stronger temperature dependent values of the relative volume fluctuations of silicon Voronoi polyhedra.

Keywords: Silicate glass, Molecular dynamics, Voronoi polyhedra, Structure, Fluctuations