[摘要]：We report on the structural, morphological and optical characterization of glass and glass-ceramic samples, with nominal composition of 91SiO(2):4Li(2)O:4Nb(2)O(5):1Dy(2)O(3) (% mole). The samples were heated treated in air in the temperature range between 500 degrees C and 800 degrees C. The glass-ceramics samples start to crystallize at temperatures above 600 degrees C and besides the SiO(2) and LiNbO(3) crystalline phases, sub micron DyNbO(4) precipitates were identified by X-ray diffraction and scanning electron microscopy for temperatures above 750 degrees C. Using Raman spectroscopy was possible to identify the vibration modes assigned to the crystalline phases detected by the XRD analysis. Also, the performed Photoluminescence Spectroscopy analysis suggest that the optical activation of Dy(3+) ions in the glass and glass-ceramics hosts was found to be dependent of the heat treatment temperature. Intraconfigurational transitions between the (4)F(9/2) and (6)H(J(-15/2. 13/2)) multiplets of Dy(3+) ions were only observed for samples without the presence of the DyNbO(4) crystalline phase. Moreover, for samples heat treated between 500 degrees C and 700 C the intensity ratio of the (4)F(9/2) (6)H(13/2) and (4)F(9/2) (6)H(15/2) transitions of the lanthanide ion changes, suggesting different ion environments which are dependent on the thermal annealing temperature. The dielectric measurements revealed that epsilon' value depends mainly in the number of network modifier ions and the relaxation phenomenon observed at frequencies above 10 kHz, in all samples, can be assigned to the increase of the volume ratio between the LiNbO(3) particles and the glass network. (C) 2011 Elsevier B.V. All rights reserved.
