Structural investigations of sol–gel-derived LiYF4 and LiGdF4 powders

Structural and optical characterizations of sol–gel based composites constituted of LiGdF4 : Eu3+ nanocrystallites dispersed into a silica matrix

“…10 The signal observed between 750 and 400 cm À1 , it can be attributed to the fluoride lattice vibrations according previous works. 11,12 In order to evidence the LiGdF 4 phase crystallization, a far-IR study was also performed and is presented in Fig. 4.…”

Photoluminescence of Eu3+, Tb3+ and Tm3+-doped transparent SiO2–Al2O3–LiF–GdF3 glass ceramics

“…From these profiles, it is observed that the as-made glass is completely amorphous with no sign of diffraction peaks. After crystallization by thermal treatment at 650 • C for 3 h, the XRD profile show intense diffraction peaks, which could be assigned to the well crystallized phases of LiGdF 4 with inverse scheelite structure ( [13], JCPDS-file 27-1236). Although some peaks of impurity phase (GdF 3 ) are detected, it should be pointed out that their peak intensities are weak compared to those of LiGdF 4 .…”

Novel sol-gel SiO2-NaGdF4 transparent nano-glass-ceramics

“…Moreover, in TEOS/MTES samples, the bands associated to Si-CH 3 still appear after the heat treatment at 550°C, indicating that the organic compounds related to the MTES are not completely removed. A band centered at 450 cm −1 is observed for OxGCs and it is associated to a fluoride lattice according to Leproute et al [39,49]. Therefore, very low content of OH groups has been obtained in the glass-ceramic materials.…”