Structural analysis of molten V2O5

Abstract

The structure of molten V₂O₅ has been investigated using a radial distribution function based on X-ray scattered intensity data collected at 750 °C; analysis was by the correlation method. The average V—O distance of 1.75 Å in the melt is shorter than that of 1.82 Å in the crystal and the coordination number of 3.9 in the melt is smaller than that of 5.0 in the crystal. The most probable model for molten V₂O₅ is similar to the crystal structure of P₂O₅ or SiO₂. Each VO₄ tetrahedron is surrounded by three VO₄ tetrahedra and the V—V distance of 3.44 Å is almost equal to twice the V—O distance. The estimated density of the model assuming the cristoballite-like structure is 2.4 g cm^–3, while the measured density is 2.15 g cm^–3.