Structural And Optical Properties Of Nickel Zinc Alumino-Gallo-Silicate Glass

Transparent glass-ceramic was obtained from ZnO-Ga2O3-Al2O3-SiO2 glasses. The colour drastically changed from brownish yellow to green on heat treatment between the glass transition and crystallisation temperatures. The crystalline phase precipitated in the treatment was identified as spinel type crystal, by x-ray diffraction measurements. Transmission electron microscope observations confirmed that the crystalline size was about 10-15nm in diameter. Broadband near-infrared emission was observed from the transparent glass-ceramic with the excitation by 976nm. It was thought that the spinel nano-crystallites containing Ni should act as the emission centre.