STRUCTURAL INVESTIGATION OF P2O5-Na2O-Cr2O3 GLASS SYSTEM

Carla Cîmpean and I. Ardelean

Faculty of Physics, Babes-Bolyai University, 400084 Cluj-Napoca, Romania

      Phosphate glasses are both scientifically and technologically important materials because they generally offer some unique physical properties better than other glasses, such as high termal expansion coefficients, low melting and softening temperatures, high electrical conductivity, ultraviolet transmission and optical characteristics [1].
      Glasses of the xCr2O3.(100-x)[ P2O5.Na2O] systems, with 0  x  15 mol%, were prepared and investigated by FTIR and Raman spectroscopy in order to determine their local structure.
      In the IR spectrum of the glass matrix absorption bands appear that are assigned to phosphate units, but the characteristic bands of Na2O are not evidenced. The addition of Cr2O3 to the glass matrix determines some changes in the IR spectra. The bands ascribed to the specific vibration of Cr-O bonds are evidenced only for high content of Cr2O3. Similar structural modifications are evidenced in the study of Raman spectra of                     xCr2O3.(100-x)[ P2O5.Na2O] glass system.
      The results have shown that phosphate units are the main structural units of the glass system and the chromium ions are located in the network. The increase of the chromium ions content influences the structure of glasses.

   References

1. A. Chahine, M. Et-tabirou, M. Elbenaissi, M. Haddad, J. L. Pascal, Effect of CuO on the Structure and Properties of (50 – x/2)Na2O-xCuO-(50 – x/2)P2O5 Glasses, Materials Chemistry and Physics 84, 341-347, 2004