Structure Evolution And Optical Properties Of Co-Doped Zinc Aluminosilicate Glass-Ceramics

Temperature induced structure evolution of zinc aluminosilicate glasses nucleated by TiO2 and doped with cobalt oxide was studied by small angle x-ray scattering, x-ray diffraction analysis, Raman and optical spectroscopy. According to the SAXS data, the phase separation by spinodal decomposition that occurred during glass melt cooling and annealing proceeded upon further heat-treatments. Cobalt oxide facilitated amorphous phase separation of the parent glass that resulted information of a cobalt-doped amorphous zinc aluminotitanate phase and gahnite, ZnAl2O4, cyrstals. Cobalt-doped gahnite nanometer sized crystals were formed at temperatures as low as 720 deg C and remained the only crystalline phase if heat treatment temperature did not exceed 950 deg C.