Studying of optical and morphological properties of SiO2–MOx (M: Co/Cu) glasses prepared by the sol–gel method

The cobalt oxide-silica and copper oxide-silica glasses are prepared by the sol–gel method. Tetra-Ethyl-Ortho-Silicate (TEOS) is used as source of the silica and transition metal nitrate is used as the dopant. The morphological, structural and optical properties of the samples are investigated by Scanning Electron Microscope (SEM), Energy Dispersion Analysis by X-ray (EDAX), X-ray diffraction (XRD) and Ultra-Violet/Visible (UV/Vis) spectrophotometer. The influences of heat treatment temperature and withdrawal rate on absorption/transmission spectra are investigated in the range 400–800 nm. In the cobalt oxide-silica, the intensity and position of absorption bands (λmax) are changed by heat treatment. These behaviors are explained through the Bathochromic and the Hyperochromic effects. In addition, the effect of the withdrawal rate on transmission curves is explained in terms of the Levich equation and Beer–Lambert law.