Spectroscopic properties of new cubic tungstates doped with Eu3+and Yb3+ions

Abstract

The motivation for this research was to find nanoscale tungstates with cubic structure, which then can be used to obtain the transparent ceramics. To our best knowledge any transparent ceramics of the rare-earth doped tungstates are not known and described in the literature, so obtaining them is therefore a great challenge. Two new classes of cubic compounds doped with Eu3+and Yb3+ions i.e. nano-and microcrystalline tungstates of chemical formula Ba3Y2WO9(Fig. 25.1) and microcrystalline BaLaLiWO6were synthesized by sol-gel method. For Ba3Y2WO9X-ray diffraction (XRD) analysis demonstrates single-phase nanopowders with high crystallite dispersion, and confirmed crystallization in cubic perovskite with the space group Fm-3m. However, for BaLaLiWO6only microcrystalline powder, despite the use of the same conditions of synthesis, confirmed by SEM method was obtained. The luminescence excitation and emission spectra in the ultraviolet-visible (UV) and NIR region at room and low temperature were used to investigate the optical properties of these phosphors. The investigations were completed by the site-selective excitation with luminescence and decay measurements. The comprehensive spectroscopic results was presented and discussed in depth.