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

The iron doped glasses with composition close to the commercially produced E-glass, approximated by a five component system MgO–CaO–B₂O₂–Al₂O₂–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.