Ceramics-Silikáty 53 (3) 180-183 (2009)

SPECTROSCOPIC ANALYSIS OF IRON DOPED GLASSES WITH COMPOSITION CLOSE TO THE E-GLASS: A PRELIMINARY STUDY

R. Klement, J. Kraxner, M. Liška

The iron doped glasses with composition close to the commercially produced E-glass, approximated by a five component system MgO–CaO–B₂O₃–Al₂O₃–SiO₂, were studied by UV VIS NIR spectroscopy. The calibration of the absorbance with respect to Fe²⁺ concentration allowed to determine the extinction coefficient for Fe²⁺ species for this type of glasses; at 10000 cm^-1 was found to be 15.99 ± 0.09 dm³.mol^-1.cm^-1. The iron redox ratio, Fe²⁺/ΣFe, was determined from the spectra. It was found that redox ratio increases with the increasing amount of alkaline-earth oxides in the glass. Principal component analysis of the set of studied spectra (in the range form 6700 cm^-1 to 18000 cm^-1) resulted in two to three independent spectral components. Deconvolution of the spectral bands centred at about 5000 cm^-1 and 10000 cm^-1 showed that Fe²⁺ ions in studied glasses are predominantly in octahedral coordination.

Keywords: UV-VIS-NIR, Optical spectroscopy, Iron, Redox state of glass, E-glass