Structural analysis of molten Ag2SO4

Abstract

The structure of molten Ag₂SO₄ has been investigated by the radial distribution function based on X-ray scattered intensity data collected at ≈ 720°C and has been analysed by the correlation method. The SO₄ tetrahedron is proved to exist in the molten state. The most likely model within an Ag₂SO₄ unit is that one of the two Ag atoms occupies the corner-sharing site with an average Ag–O distance of 2.25 Å and the other occupies the edge-sharing site with an average Ag—O distance of 2.68 Å. The most likely model for the long-range arrangement within 10 Å is similar to CaF₂-type packing where Ca and F are replaced by SO₄ and Ag, respectively. One Ag₂SO₄ unit is surrounded by ≈ 18 Ag₂SO₄ units with an average inter-unit distance of 6.2 Å.