Effect of crystallization of Li2O-Al2O3-SiO2 glasses on luminescence properties of Nd3+ ions

Generally the preparation of lithium aluminosilicate (LAS) glasses is difficult on account of their high melting temperature. This research managed to prepare LAS glasses doped with Nd3+ ions by the conventional melting and quenching technique, at a relatively low melting temperature and by the use of some additives. Lithium aluminosilicate glasses were transformed to glass-ceramics by controlled nucleation and the crystallization process. The characterizations were performed by differential thermal analysis, X-ray diffraction, UV-Vis-NIR scanning spectrophotometry, and fluorescence spectrometry. The research focused on the photoluminescence spectra of the initial glass and the glass-ceramics under different heat-treatment schedules. Three main fluorescence bands centering at about 890, 1065, and 1330 nm were observed, which corresponded to the transitions of F-4(3/2)-> I-4(9/2), F-4(3/2)-> I-4(11/2), and F-4(3/2)-> I-4(13/2), respectively. Phase compositions of glass-ceramics were found to affect their fluorescent characteristics considerably. The fluorescent intensity increased markedly when Nd3+ ions entered the LixAlxSi1-xO2 beta-eucryptite solid solution (SS). Quenching occurred when Nd3+ ions located at LixAlxSi3-xO6 beta-eucryptite SS. Quenching disappeared after LixAlxSi3-xO6 beta-eucryptite SS recrystallized into beta-spodumene SS. The effectively induced cross section sigma(in) of Nd3+ ions located at the LixAlxSi1-xO2 beta-eucryptite SS was 1.931 X 10(-21) cm(2) at 1065 nm.