Spectral investigation of crystalline (CuHPO4, Cu2P4O12 and Cu2P8O22) and glassy copper phosphates

Emerald green crystals of the new composition CuHPOwere synthesized and compared to (copper metaphosphate) CuHPO4, Cu2P 4O12 and (copper ultraphosphate) Cu Various copper ultraphosphate and metaphosphate glasses of different compositions between pure P2O5 and Cu2P4O12 were melted in crucibles or in evacuated and sealed silica ampoules at 1473 K or 1373 K for 2 hrs. The UV-VIS-spectra and the IR-spectra of all crystals and glasses were measured and compared. The absorption band of Cu2+ was resolved into more component Gaussian bands and differentiated between square-pyramidal and octahedrally coordinated copper. These structural changes are responsible for colour changes from green to turquoise. The infrared spectroscopic properties of the copper phosphate glasses differ between metaphospha te and ultraphosphate structures but show similarities between the crystals and the glasses of the same structure type. EPR studies of some of the glasses show different kinds of spectra, with increasing copper content

VANADATE SEMICONDUCTING GLASSES DOPED WITH OXIDES OF OTHER TRANSITION METALS

The EPR spectra, electrical conductivity and activation energy have been measured in barium-vanadate glasses doped with CuO, Mn2O3, Fe2O3, Co2O3 and Cr2O3 impurities in concentration from 0.1 to 7 wt.%. The results are interpreted in terms of distinct interactions between vanadium and impurity ions