The vibrational spectra of crystalline W 2O 3(PO 4) 2 and related tungsten phosphate glasses

Abstract

IR and Raman spectra were measured and analyzed for crystalline W 2O 3(PO 4) 2. Factor group analysis indicates that the observed vibrational spectra can be interpreted better with the earlier determined space group P2 1 m−C 2 2h than with the space group P2 1− C 2 2. Band assignments for this material are consistent with those made earlier for related materials. IR spectra indicate that the short range order of glasses with compositions close to W 2O 3(PO 4) 2 crystals are similar to that of the latter crystalline material. As the WO 3 concentration increases in the glasses, the number of WO 6-octahedra possessing only W-O single bonds increases in the glass structure. PO bonds are found in the tungsten phosphate glasses containing higher P 2O 5 contents.