Vol. 30, Issue 4, pp. 691-699 (2000)

Abstract

The X-ray scattering data for CaO-Ga₂O₃-GeO₂ glasses of stoichiometric compositions similar to that of calcium-gallium-germanium garnet (Ca₃Ga₂Ge₃O₁₂) Ca-gallogermanate (Ca₃Ga₂Ge₄O₁₄) and Ca₃Ga₂O₆ crystals are presented. Experimental results show the true glass structure of the compounds under investigation. A comparative analysis of the X-ray data for glasses and their crystalline analogies has shown that the glass network consists of gallium and germanium oxygen co-ordinated octahedra and tetrahedra. The results obtained have been compared with the results of preliminary molecular dynamics (MD) calculations of the structure of CaO-Ga₂O₃-GeO₂ glasses. The pair distribution functions (PDFs) obtained from the MD simulation, show satisfactory agreement with the X-ray data The building blocks of the CaO-Ga₂O₃-GeO₂ glass network have been proposed. The structure peculiarities of the glasses and their crystalline analogies are discussed.