2010, Volume 13, Issue 1
FTIR and EPR Spectroscopic Characterisation of Iron-Tellurite Glasses Obtained by the Sol-Gel Method
1 National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Str. 400293 Cluj-Napoca, Romania
2 Department of Physics, Technical University of Cluj-Napoca, 400020, Cluj-Napoca, Romania
3 Faculty of Chemistry and Chemical Engineering, 400028, Babes-Bolyai University, Cluj-Napoca, Romania
Iron-tellurite glasses were obtained using the sol-gel method. The samples were characterized by X-ray diffraction, FTIR and electron paramagnetic resonance (EPR) spectroscopy. FTIR data reveal that the vitreous network of the studied glasses are based on TeO6, TeO4 and TeO3 structural units. The increase of the Fe2O3 content modify progressively the structure of the host glass matrix. The local structure in the studied glasses was investigated by means of EPR using Fe3+ (3d5; 6S5/2) ions as paramagnetic probes. The EPR spectra present two absorption lines characteristic of Fe3+ ions centered at geff»2.0 and geff»4.3. The existence of the resonance lines at geff»4.2 at low concentration was attributed to isolated Fe3+ ions located in distorted octahedral symmetry (rhombic or tetrahedral). By increasing the iron concentration the local ordering of the Fe3+ ion vicinities is destroyed and, consequently, the line at g around 4.2 disappears while that from geff» 2.0 increases in intensity.
Iron-tellurite glasses, FTIR, UV-VIS, EPR spectroscopy, sol-gel.
Tag search Iron-tellurite glasses FTIR UV-VIS EPR spectroscopy sol-gel