Transparent Ni2+-doped lithium aluminosilicate glass-ceramics with broadband infrared luminescence

Transparent Ni2+ -doped Li2O-Al2O3-SiO2 glass-ceramics were prepared. beta-Eucryptite nanocrystals were precipitated from the glass matrix after heat-treatment. X-ray diffraction analysis revealed that the crystallite sizes were 30-40 nm, and the average size increased with increasing temperature. Broadband infrared luminescence centered at around 1300 rim with full width at half maximum (FWHM) of more than 300 nm, was observed from the Ni2+ -doped glass-ceramic heat-treated at 650 degrees C for 2 h. Optical absorption spectra indicated that Ni2+ ions moved from trigonal bipyramid five-fold sites in the as-made glass to octahedral sites in the glass-ceramics at first, and then to distorted octahedral sites with increasing temperature. The blue-shift of the peak position and the intensity decrease of the infrared luminescence could be attributed to the sites change of Ni2+ ions in the glass-ceramics. (C) 2007 Elsevier B.V. All rights reserved.