Effect of additive ions on the optical density and stability of the color centers induced by X-ray irradiation in soda-lime silicate glass

To apply radiation-induced coloration of glasses as a reversible glass-coloring technique, we studied the influence of various additive ions incorporated into a soda-lime silicate glass on the optical density and stability of the color induced by X-ray irradiation. Absorption spectra before and after irradiation are discussed in the comparison with those of the undoped soda-lime silicate glass. Additive ions were incorporated as metal oxides, namely TiO2, V2O5, Fe2O3, ZnO, Ga2O3, GeO2, ZrO2, Nb2O3, MoO3, Ag2O, In2O3, SnO, SnO2, CeO2, Eu2O3, Ta2O5, WO3 and Bi2O3. Among them, TiO2, GeO2, Nb2O3, MoO3, Ag2O, In2O3, Eu2O3, Ta2O5, WO3 and Bi2O3 have a large effect on optical density. The optical densities in the visible region for glasses doped with these oxides were much stronger than for undoped soda-lime silicate glass. On the other hand, incorporation of Fe2O3, SnO and CeO2 reduced the optical density. Over longer periods the coloration of the undoped glass was one of the most stable while those of the Fe2O3, SnO and CeO2-doped glasses soon faded.