THE OPTICAL, ELECTRICAL AND DENSITY PROPERTIES OF GAMMA-IRRADIATED ALKALI-BORATE GLASSES CONTAINING SOME TRANSITION-METALS

The change of optical absorption of some gamma irradiated alkali-borate glasses containing Ti, V, Mn, Fe, Ni or Cu has been studied. Moreover, the electrical conductivity and density have been measured for the examined glasses before and after irradiation by several gamma doses ranging from 5.4 to 543 kGy. The effect of the irradiation dose and the role of transition metal oxides have been investigated and the changes in optical spectra of the base glass and other derived glasses after irradiation with gamma rays are compared. Upon increasing the irradiation dose different rates of the colour center formation have been observed. The values of the optical densities of the absorption peaks increase till they reach nearly equilibrium or saturation, after which no obvious increase has been observed. After exposing the glass to gamma rays the electrical conductivity and density values show an increase at first followed by a decrease in their values, while the values of densities after prolonged irradiation continue to decrease and then remain nearly constant. The addition of different transition metals shows a remarkable increase in the electrical conductivity and density values which are probably due to their own electronic configurations. The fading in the band intensities, electrical conductivities and density values after several interval days at room temperature have also been studied.