Ceramics-Silikáty 53 (1) 52-54 (2009)

MD structural study of 23Y₂O₃-77Al₂O₃ and 23La₂O₃-77Al₂O₃ glasses

P. Perichta, M. Liška, J. Macháček, O. Gedeon

The ab-initio molecular dynamics (MD) calculations of the yttrium aluminate and lanthanum aluminate binary systems 23R₂O₃•77Al₂O₃ (R = Y, La) were performed with help of the Vienna ab-initio simulation package VASP. Both the R-O equilibrium distances and R/O and Al/O coordination numbers calculated from the partial pair radial distribution functions (PP RDF) obtained for MD simulated glass at the temperature of 300 K are in a reasonably good agreement with the published neutron diffraction and X-ray diffraction studies. The structural differences between glasses studied by MD calculation were attributed to the higher network modifying activity of the lanthanum oxide which comes from the higher electropositivity and bigger ionic radius of lanthanum in comparison with yttrium.

Keywords: Molecular dynamics, Ab initio, Structure, Yttrium/lanthanum-aluminate glass