%0 Journal Article %A Cremades Rodríguez, Ana Isabel %A Santos, M. T. %A Remon, A. %A García, J. A. %A Dieguez, E. %A Piqueras de Noriega, Javier %T Cathodoluminescence and photoluminescence in the core region of Bi_12GeO_20 and Bi_12SiO_20 crystals %D 1996 %@ 0021-8979 %U https://hdl.handle.net/20.500.14352/58862 %X Cathodoluminescence and photoluminescence of Bi_12SiO_20 and Bi_12GeO_20 samples are studied. Both kinds of samples show a dark orange central part or core. Emissions in the blue, green, and red spectral regions are observed. The 640 nm band is the predominant feature in the core emission. The evolution of this band during electron irradiation suggests possible emission mechanisms. In addition, two infrared emissions at about 915 and 1390 nm are detected. %~