SIMULTANEOUS GENERATION OF OPTICAL-ABSORPTION BANDS AT 5.14 AND 0.452 EV IN 9 SIO2-GEO2 GLASSES HEATED UNDER AN H2-ATMOSPHERE

Nine SiO2: GeO2 glasses were heated under an H 2 or O2 atmosphere. In the H2 atmosphere optical absorption bands were induced at vacuum ultraviolet (VUV) (>6.22 eV), 5.14 eV (242 nm), 3.82 eV (325 nm), and 0.452 eV (2.75 μm). The intensities of all the induced bands are in linear relation with each other. Heat treatment in the O2 ambient reduced the intensities of the optical absorption bands. A model for the reaction of the glasses with H2 molecules and a structural model of the center responsible for the UV-VUV absorption was proposed.