Nd2(WO4)3
نویسندگان
چکیده
The title compound, dineodymium(III) tris-[tungstate(VI)], is a member of the Eu(2)(WO(4))(3) structure family and crystallizes isotypically with other rare earth tungstates and molybdates of this formula type. The structure is a derivative of the scheelite (CaWO(4)) structure and can be considered as an ordered defect variant with a threefold scheelite supercell and one rare earth (RE) site unoccupied. The Nd(3+) cations are coordinated by eight O atoms in form of a distorted bicapped trigonal prism. The two unique W cations are tetra-hedrally surrounded by O atoms. One WO(4) tetra-hedron has 2 symmetry and is relatively undistorted whereas the other tetra-hedron differs considerably from an ideal geometry. This is caused by an additional remote O atom at a distance of 2.149 (4) Å. The resulting WO(4 + 1) polyhedra form W(2)O(8) dimers through edge-sharing. Together with the WO(4) and NdO(8) units, the three-dimensional set-up is accomplished.
منابع مشابه
A 35 : Impurity - doped Micro - lasers
Rare-earth-ion-doped monoclinic potassium double tungstates KY(WO4)2, KGd(WO4)2, and KLu(WO4)2 are excellent host materials for solid-state lasers [1]. High-quality KY(WO4)2 optical waveguides were grown and laser operation was demonstrated for the first time [2]. Co-doping a KY(WO4)2 layer with Gd 3+ and Lu 3+ ions allows for lattice-matched layers with increased refractive index contrast with...
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The infrared and Raman spectra of Ce2(WO4)3 and La2(WO4)3, which are complicated by the superposition of bands from two non-equivalent WO4 units, have been successfully assigned above 300 cm −1 according to Td point group symmetry. Individual assignment of the two types of tungstate units, WO4 (C2 site symmetry) and W O4 (C1 site symmetry), relies on comparison with the spectra of tetrahedral r...
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The potassium double tungstates KGd(WO4)2, KY(WO4)2, and KLu(WO4)2 are excellent candidates for solid-state lasers, see Ref. [1] and Refs. therein, because of their high refractive index of ~2.02.1, the large transition cross-sections of rare-earth (RE) ions doped into these hosts, the possibility to incorporate very large concentrations of RE 3+ ions, reaching the stoichiometric structure KRE(...
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