Lattice Locations of 12B in CaB6

2002 ◽  
Vol 57 (6-7) ◽  
pp. 617-619 ◽  
Author(s):  
M. Mihara ◽  
K. Hashimoto ◽  
K. Arimura ◽  
S. Kudo ◽  
K. Akutsu ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Quadrupole Interaction ◽  
Room Temperature ◽  
Nuclear Quadrupole Interaction ◽  
Nmr Studies ◽  
Nuclear Quadrupole ◽  
Lattice Locations ◽  
La Doped

The nuclear quadrupole interaction of the short-lived -emitter 12B implanted into CaB6 crystal has been studied by means of modified β-NMR (β-NQR) technique. The electric field gradient at the implanted 12B was found to be = q-(1.34±0.05)x1021 V/m2 at room temperature. From this result it is concluded that the 12B probe nuclei are mainly implanted in the substitutional boron site and are applicable to systematic NMR studies of ferromagnetic La doped CaB6

The Nuclear Quadrupole Interaction of 204mPb in Cadmium Monitored by γ–γ –Perturbed Angular Correlations

2002 ◽  
Vol 57 (6-7) ◽  
pp. 586-590 ◽  
Author(s):  
W. Tröger ◽  
M. Dietrich ◽  
J. P. Araujo ◽  
J. G. Correia ◽  
H. Haas
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Plane Waves ◽  
Nuclear Quadrupole Interaction ◽  
Full Potential ◽  
Angular Correlations ◽  
Time Differential ◽  
On Line ◽  
First Time

For the first time the nuclear probe 204mPb was produced at the on-line isotope separator ISOLDE at CERN and used for time differential perturbed angular correlation experiments. The electric field gradient of 204mPb at room temperature in Cd metal was determined to be = 19(1) 1021 V/m2. Ab initio-calculations of the electric field gradient for the impurities Pt to Bi in cadmium were performed with the full-potential linearized augmented plane waves code WIEN97 to interpret this result. For Au, Hg and Pb, where experimental results are now available, these agree with the calculations within 10 %.

The Electric Field Gradient at the Site of the Halogen Ion and Structure of Amino Acid Hydrobromides and Hydroiodides

1992 ◽  
Vol 47 (7-8) ◽  
pp. 887-917
Author(s):  
Armin Kehrer ◽  
Shi-qi Dou ◽  
Alarieh Weiss
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Room Temperature ◽  
Low Frequency ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Resonance Frequencies ◽  
Quadrupole Coupling ◽  
Frequency Coupling

Abstract The 79,81Br and 127I NQR spectra of several hydrobromides, respectively hydroiodides, of amino acides and dipeptides were studied, mostly as functions of temperature in the range 77 < T/K <420. The investigated compounds are: L-Arg • HBr • H2O, L-Cys • HBr • H2O , L - Cys - S - S - L - Cys • 2HBr, ethanolamine • HBr, L-Glu • HBr, L-His • HBr, L-His • 2HBr, L-Ile HBr • H2O , Sar • HBr, (Sar)2 • HBr, L-Val • HBr • H2O , Gly • LiBr, Gly-Gly • LiBr, ethanolamine HI, Sar • HI, (Sar)2 • HI, (Gly)2 • HI, (L-Val)2 • HI, Gly-L-Leu • HI • H2O . A phase transition with hysteresis was observed for L-Val • HBr • H2O (Tc.up = 318 K, Tc.down = 242 K). Two solid phases of Sar • HI have been studied by NQR, one crystallized from melt, the other one from aqueous solution. For three of the title compounds the crystal structure was determined at room temperature: L-His - 2HBr, P212121 , Z = 4, aj pm = 1652, b/pm = 916, c/pm = 721; L-Cys HBr H2O , P212121 , Z = 4, a/pm = 1955, b/pm = 746, c/pm = 550; Gly-L-Leu • HI • H2O , P2X, Z = 2, a / p m = 1289, b/pm = 914, c/pm = 615, ß/° = 99.In most cases the halogen ion in the studied hydrohalides is polycoordinated by hydrogen bonds of the type N - H • • • X⊖ and O - H • • • X⊖ , X = Br, I. The NQR frequencies and, for iodine, the nuclear quadrupole coupling constants depend on this coordination. A low frequency (coupling constant) region is found for pure N - H • • • X⊖ coordination. Replacing one N - H • • • X⊖ bond by O - H • • • X⊖ rises the electric field gradient, EFG, respectively the resonance frequencies. The dependence of the EFG on the hydrogen bond coordination N - H • • • X⊖ plus O - H • • • X⊖ is discussed for the title compounds including information from literature

scholarly journals Electric field gradient at the 111Cd(←111In) site in Ga-doped ZnO

2011 ◽  
Vol 1 (1) ◽  
pp. 435-438 ◽  
Author(s):  
W. Sato ◽  
Y. Ohkubo ◽  
Y. Itsuki ◽  
S. Komatsuda ◽  
D. Minami ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Room Temperature ◽  
Local Environment ◽  
Relative Width ◽  
Probe Nucleus ◽  
Tdpac Spectrum ◽  
Time Differential ◽  
Doped Zno

AbstractThe time-differential perturbed angular correlation (TDPAC) method was applied to a study of the local environment at the 111Cd(←111In) probe nucleus introduced in 0.5 at. % Ga-doped ZnO. The TDPAC spectrum obtained at room temperature suggests that the doped Ga ions reside at the substitutional Zn site and they are locally associated in immediate proximity to the probe, reflecting strong attractive force between the probe and the dopants. The relative width of the magnitude of the electric field gradient produced at the probe nucleus shows that the doped Ga ion(s) adjacent to the probe is/are diversely distributed compared with doped In ion(s).

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