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N. Vedeanu, O. Cozar, I. Ardelean, B. Lendl, D. Magdas:
"Raman spectroscopic study of CuO-V2O5-P2O5-CaO glass system";
Vibrational Spectroscopy, 48 (2008), S. 259 - 262.

n order to evidence the structural changes induced by CuO and V2O5 in the phosphate glass network and their modifier or former role, x(CuO×V2O5)(100 - x)[P2O5×CaO] glass system was prepd. and investigated using Raman spectroscopy (0 £ x £ 40 mol%). Raman spectra of the studied glasses present the specific bands of the phosphate glasses at low concn. of transition metal (TM) ions, but at higher concn. (x > 7 mol%) a strong depolymn. of the phosphate network appears; non-bridging oxygen atoms are involved in V[sbnd]>O[sbnd]>P and Cu[sbnd]>O[sbnd]>P bonds and new short units are formed. For a high concn. of V2O5 (x > 10 mol%) the Raman bands of V2O5 prevail in the spectra; this fact suggests that vanadium oxide imposes its structural units in the network acting thus as a network glass former. 2D correlation anal. was also applied for the concn.-dependent Raman spectra in order to verify the assignments of the vibration modes and to find correlations in the changes induced by TM ions content. 2D correlation maps indicate a good correlation between the bands at .apprx.705 cm-1 assigned to P-O-P stretching vibration and at .apprx.1175 cm-1 assigned to PO2 groups which suggest the depolymn. of the phosphate network. The correlation between the 1270 cm-1 and 930 cm-1 bands also suggests that V2O5 oxide is responsible for P=O bonds breaking and P-O-V formation.