Preparation and characterization of phosphate glass system A2MnMP2O10 (A = Li, Na, K) and (M = W, Mo)

Abstract

New materials based glassy phosphates and transition elements A2MnMP2O10 (A = Li, Na, K) and (M = Mo, W) were prepared by direct fusion of the mixture of the reactants followed by quenching in the air. Analysis by X-ray diffraction showed that the obtained materials are amorphous. Differential scanning calorimetry DSC was used to determine the glass transition (Tg) and crystallization (Tc) temperatures. The thermal stability of tungsten glasses is higher than that of molybdenum ones. Tungsten plays, certainly, a role of cross-linking polyphosphate groups by creating more covalent new bonds P-O-W and W-O-W. Moreover, it has been shown that lithium glasses are more stable than sodium and potassium, probably due to the potassium hygroscopy. Raman analysis confirms that the studied glasses have similar structures and the predominant structural units are PO4, P2O7 and MO6 polyhedra (M = W, Mo, Mn).