Neodymium single crystal

The single crystal X-ray structure of hydrated neodymium hypophosphate, NdHP206-4H20, has been determined.239 The Nd ion is eight-coordinated to four H20 and two bidentate hypophosphate anions. The details of interatomic distances and bond angles were compared with other members of this isostructural series, which extends at least from Nd to Er.240... 

The quantum yields of fluorescence of the different systems have also been determined relative to a single crystal of neodymium-doped YAG for which a quantum yield of unity has been assumed (Heller, 1968a). The quantum yields obtained, even if they are accurate only within a factor of two, follow the same trend as for the lifetimes, with the highest values for the acidic solutions 0.70 and >0.75 in presence of S11CI4 and SbCls, respectively. Neutral and basic solutions are less luminescent and have quantum yields of 0.5 and 0.4, respectively. Identical measurements performed on a sodium-compensated neodymium-doped calcium tungstate crystal lead to a value of 0.5. The high quantum efficiency and the low threshold (between 2 and 40 J) of these Nd3+ SeOCl2 systems clearly demonstrate that liquids are not inherently inferior to solids as laser materials. 

Compound 65f was isolated as a sky-blue crystalline solid which is highly soluble in nonpolar organic solvents. The molecular structure of 65f was determined by a single crystal X-ray analysis. It showed the neodymium atom in a distorted octahedral coordination environment (Fig. 20) [78]. Dark red crystalline [Me2Si(OtBu)(NrBu)]3Eu was prepared analogously. 

Comparative studies of neodymium measurements in UOj fuel for the future application of local burn up calculations have been carried out by the SIMS analysis of a Nd implanted UOj single crystal. Samples for a round robin test were produced by the implantation of " Nd (5 x 10 ° at cm , 400 keV) in a UOj single crystal. Different depth profiles of the Nd "/ U+ ratio and especially the NdO /Nd, UO+/U+ and U02 /U+ ratios obtained by SIMS are not constant over time and indicate evidence of some fluctuations during the analysis. SIMS plays a dominant role for particle analysis, but also LA-ICP-MS with lower spatial resolution can be applied to identify anomalies in the isotopic composition of radionuclides. 

X-ray diffraction studies on single crystals of NdFe oSiCo 5 have established its structure with the space group I4i/amd and Z = 4 formula units per unit cell. The positions of the neodymium, iron and silicon atoms correspond to the BaCdn structure. The positional and thermal parameters for NdFejoSiCo s of BaCdj, type structure have been given by Le Roy et al. (1987), as well as the interatomic distances in this compound. This structure is a disordered version of LaMnnC, 52 (Ross et al. 1981). Each neodymium atom is surrounded by a polyhedron of 26 atoms, i.e. 18 iron atoms, four carbon atoms and four atoms which may be iron or silicon. Fe(l) is surrounded by 14 atoms, Fe(2) by 13 atoms, and the (Fe-Si) site by 12 atoms. As has been pointed out, the carbon atoms fill octahedral voids formed by four iron atoms and two neodymium atoms, with an occupancy of 25%. 

Fig. 8.61. Young s (E), shear (G), and bulk K) moduli of neodymium computed from the single crystal data in flg. 8.60.

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