Abstract
Ultraphosphate glasses in the system CuO-P2O5 were prepared from 0 to 18 mol% CuO (synthesis) starting from powdery P4O10 (p. a. Merck) and fresh prepared Cu2P4O12 in closed SiO2 glass ampoules between 1000° and 1100°C for about 2 hours. After cooling with about 10 K min-1, the ampoules were stored under paraffin oil in a desiccator and handled with exclusion of “water”. Measurements of density, chemical composition, optical and infrared spectroscopy followed. The optical spectra only show Cu2+, but in different positions, depending on CuO content. Cu+ was not found, although the glasses were melted without air contact. The different places of the copper ions in the glass structure are connected with the structure change: With increasing content of copper more Q2 linked {PO4} tetrahedra were built. This finding strongly agrees with the infrared spectra, which show an increase of Q2{PO4} tetrahedra with increasing CuO content. The structure evolution seems to follow a binary distribution model: the (P2O5)x specific substructure units decrease, where the CuP4O11 specific substructure units increase while the CuO content increases.
