OPTICAL ABSORPTION OF IRON IN SODIUM SILICATE GLASSES: DERIVATION SPECTROSCOPY REVEALS ADDITIONAL BANDS

摘要

Sodium silicate glasses were investigated with UV-VIS-NIR~1-spectroscopy. The sodium oxide contents varied between 15 and 40 mol%, the iron concentration was 0.2 mol%. The observed change in the optical spectra of these glasses was not only due to different Fe~(3+)/Fe~(2+)-ratios, but also to a shift in the position of the ligand field bands. Derivation spectroscopy was used to determine the positions with better accuracy. It was also possible to detect additional bands in the derivative spectra.