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.