Photoluminescence spectroscopy as an attractive technique for quantitativedetermination of Fe3+ in industrial glasses

There are some cases in which absorption spectrophotometry or other "tradit ional" methods are hardly applicable to the determination of the concentrat ion of transition metal ions in glass, e.g. for particular redox states or when the glass contains several chromophores or flat polished specimens can not be prepared. Photoluminescence spectroscopy is a good alternative, especially since meas urements can be carried out on samples of any shape and size, without any p reliminary treatment. This preliminary paper reports upon [Fe2O3] determination in white, half-wh ite and green hollow glasses, aimed at verifying the ability of techniques based on photoluminescence in providing a quantitative determination of chr omophores in industrial products. The main photoluminescence band in the infra-red range is associated with F e3+. The correlation between the maximum height of this emission band and F e3+ concentration obtained by more usual procedures appears quite encouragi ng. The photoluminescence technique is particularly attractive when, as in the present case, the spectral shape does not change significatly, so allow ing a simplified procedure, consisting in the measurement of the emission i ntensity at a fixed wavelength.