The nuclear quadrupole coupling and Knight shift of ${\mathrm{Be}}^{9}$ have been measured in high-purity beryllium metal at room temperature and at 77\ifmmode^\circ\else\textdegree\fi{}K in magnetic-field strengths up to 25 kOe. The nuclear quadrupole coupling constant is found to have the value $\frac{{e}^{2}\mathrm{qQ}}{h}=61.8\ifmmode\pm\else\textpm\fi{}1.8$ kHz, independent of temperature. By contrast, the best estimate of the lattice contribution to the quadrupole coupling is found to be 68\ifmmode\pm\else\textpm\fi{}6 kHz, which implies that the conduction-electron contribution opposes that of the lattice. The Knight shift is found to have the values ${K}_{\mathrm{Be}}=\ensuremath{-}0.0025\ifmmode\pm\else\textpm\fi{}(6)$ at 300\ifmmode^\circ\else\textdegree\fi{}K and ${K}_{\mathrm{Be}}=\ensuremath{-}0.0035\ifmmode\pm\else\textpm\fi{}(6)$ at 77\ifmmode^\circ\else\textdegree\fi{}K (in percent); the uncertainty given is the standard deviation of the measurements. Measurements of the spin-lattice relaxation time at two temperatures indicate that ${T}_{1}T=1.66\ifmmode\times\else\texttimes\fi{}{10}^{4}$ sec \ifmmode^\circ\else\textdegree\fi{}K with an uncertainty of 10%. These experimental observations can be interpreted in terms of direct-contact and core-polarization contributions, from a predominantly $p$-like band, which partially cancel to yield the small Knight shift.
Neutron diffraction and magnetic susceptibility measurements have been used to characterize the structural and magnetic properties of b-Pu/sub 2/O/sub 3/ with the hexagonal La/sub 2/O/sub 3/ structure. High-resolution neutron powder patterns combined with profile analysis have given the cell constants, atomic positional parameters, and the stoichiometry with high precision. The latter is in agreement with the value determined from thermodynamic methods. The antiferromagnetic structure in the temperature range 4 K
A simple model of random electric-field-gradient inhomogeneity has been incorporated into the usual first-order treatment of quadrupolar satellites in nuclear magnetic resonance spectra in solids. Observed departures of experimental intensities from those expected strictly on the basis of transition probabilities are satisfactorily accounted for on the basis of this model.
Abstract Segregation of cations based on size is observed in samples of zeolite-A loaded with simulated radioactive-waste(∼5 wt.% Li, K, Cs and Ba, 1 wt.% Sr and Y,
Neutron diffraction and magnetic susceptibility measurements have been used to characterize the structural and magnetic properties of β-Pu2O3 with the hexagonal La2O3 structure. High-resolution neutron powder patterns combined with profile analysis have given the cell constants, atomic positional parameters, and the stoichiometry with high precision. The latter is in agreement with the value determined from thermodynamic methods. The antiferromagnetic structure in the temperature range 4 K<T<TN∼19 K consists of Pu moments in the basal plane, but they vary along the c direction in a pseudospiral way. Two components are required to describe this modulation. The value of the maximum Pu moment at 10 K is ∼0.85 μB, each component having an amplitude of ∼0.6 μB/Pu. At 4 K a spin rotation takes place so that μ∥c. Susceptibility measurements reflect the existence of TN but show very little response near the spin rotation temperature.
