Ceramics-Silikáty 50 (2) 67-72 (2006)

STRUCTURE OF SILICATE OXYNITRIDE MELT DOPED WITH SCANDIUM, YTTRIUM AND LANTHANUM: A MD DFT SIMULATION

J. Macháček, O. Gedeon, M. Liška, S. Charvátová

The MD DFT simulations of three oxynitride systems (Mg–M–Si–O–N, M = Sc, Y, La, 20 eq.% of N) were carried out. The results in the form of RDF and a coordination number were compared with the available experimental data and a good agreement was found. The main features of the experimental total RDFs were identified by means of the partial RDF originating from the simulations. Calculated coordination numbers of anions and cations were compared with the experimental data measured on both glasses and crystalline phases. It was confirmed that MD DFT can be used for bulk simulations of multi-component glassy oxynitride systems with quite reasonable results. Some discrepancies in Si-O and Si-N distances were attributed mainly to higher temperature and limited size of the systems.

Keywords: Oxynitride glass, MD DFT simulation, Scandium, Yttrium, Lanthanum