FT-NMR Detection of 45Sc, 49Ti and 93Nb in TiO2 Single Crystal

1998 ◽  
Vol 53 (6-7) ◽  
pp. 549-551
Author(s):  
K. Sato ◽  
S. Takeda ◽  
S. Fukuda ◽  
T. Minamisono ◽  
M. Tanigaki ◽  
...  

Abstract In order to determine the electric quadrupole moment of the short-lived β-emitter 41Sc from the quadrupole coupling constant in TiO2 , we measured the field gradient by detecting the Fourier-Transformed-NMR of stable isotope 45Sc doped in TiO2. Also, in order to study the electronic structure of impurities systematically, EFGs were measured for 45Sc, 49Ti and 93Nb in a TiO2 ingle single crystal.

1984 ◽  
Vol 39 (11) ◽  
pp. 1092-1103 ◽  
Author(s):  
W. H. Stolze ◽  
D. H. Sutter

The rotational Zeeman effect in the J → J′ = 0 → 1 and 1 → 2 rotational transitions has been observed for H-C≡C-C≡14N, D-C≡C-C≡14N, D-C≡C-C=15N, and H-C≡C-C=I5N using a microwave bridge superheterodyne spectrometer. From the experimental g⊥-values, susceptibility anisotropies and rotational constants, the molecular electric quadrunole moment, which plays an important role for collisional excitation and relaxation, follows as Q∥=2.14(9) x 10-26esu cm2 (referred to the center of mass of the H-C≡C-C≡14N species). Since the Deuterium quadrupole hyperfine splittings in the Zeeman spectra could be resolved, it was also possible to Fit the Deuterium quadrupole coupling constant. Our value, eqQ (2H) = 198.2(46) kHz is about 10% smaller than the value derived from a recent high resolution microwave Fourier transform study. The reasons for this discrepancy are discussed.All experimental molecular parameters are compared to the results of ab initio quantum chemical calculations and it is argued that the 14N nuclear electric quadrupole moment is possibly about 30% larger than presently assumed.


1986 ◽  
Vol 41 (1-2) ◽  
pp. 163-165 ◽  
Author(s):  
Tae-Kyu Ha

Based on the calculated electric field gradient (q) from ab initio Cl wavefunctions with largebasis set (including ƒ functions on N and d functions on H) and the experimental nuclearquadrupole coupling constant (e Q q) for nitrogen in NH3, an improved value o f the quadrupole moment of 14N is proposed as Q (14N ) = 2.08 x 10-26cm2. The value calculated using a wavefunctionnear the Hartree-Fock limit enlarged ≈ 10% by the Cl treatment.


1952 ◽  
Vol 30 (3) ◽  
pp. 270-289 ◽  
Author(s):  
G. M. Volkoff ◽  
H. E. Petch ◽  
D. W. L. Smellie

Pound's theory of the dependence of electric quadrupole splitting of nuclear magnetic resonance absorption lines in a single crystal on the orientation of the crystal in an external magnetic field is extended to cover the case of a crystal with nonaxially symmetric electric field gradient at the site of the nuclei being investigated. It is shown that an experimental study of the angular dependence of this splitting for three independent rotations of the crystal about any three mutually perpendicular axes will yield complete information about the orientation of the principal axes and the degree of axial asymmetry of the electric field gradient tensor at the site of the nuclei, and also will give the absolute value of the quadrupole coupling constant for those nuclei.The authors' experiments on the splitting of the Li7 absorption lines in a single crystal of LiAl(SiO3)2 (spodumene) are described and are used to illustrate the theory. The absolute value of the quadrupole coupling constant for the Li7 nuclei in spodumene is found to be [Formula: see text]. per sec. The axial asymmetry parameter of the field gradient tensor at the site of the Li nuclei is found to be η≡(ϕxx−ϕvv)ϕzz=0.79 ± 0.01. One of the principal axes of this tensor (the y axis corresponding to the eigenvalue of intermediate magnitude) is experimentally found to coincide with the b crystallographic axis of monoclinic spodumene as required by the known symmetry of the crystal. The other two principal axes are in the ac plane, the z axis (corresponding to the eigenvalue ϕzz of greatest magnitude) lying between the a and c axes at an angle of 48° ± 2° with the c axis.


1976 ◽  
Vol 31 (11) ◽  
pp. 1298-1302 ◽  
Author(s):  
H. Ackermann ◽  
D. Dubbers ◽  
M. Grupp ◽  
P. Heitjans ◽  
H.-J. Stöckmann ◽  
...  

Abstract Nuclear magnetic resonance measurements were carried out on neutron activated 20F(T1/2=11s) nuclei in a single crystal of KZnF3. The quadrupolar splitted NMR spectrum, detected via the 20F β-radiation asymmetry, could be observed using a radio frequency modulation technique. The quadrupole coupling constant was determined to e2 q Q/h= + (12.0 ± 1.5) MHz at room temperature. The sign of e2 q Q was obtained from a simultaneous γ-ray anisotropy measurement on the succeeding 20Ne transition. Utilising a calculated field gradient of the fluorine atom, an fQ = 4.6% is determined. This value is compared with literature data of similar compounds.


1955 ◽  
Vol 33 (6) ◽  
pp. 286-297 ◽  
Author(s):  
R. G. Eades

The nuclear magnetic resonance spectrum of Al27 in a single crystal of HBeAlSiO5 (euclase) in an external magnetic field of 7000 gauss is described. The Al27 nuclei are found to occupy two kinds of lattice sites which differ from each other only in the orientation of the principal axes of the electric field gradient tensors whose eigenvalues are all distinct, but identical at both sites. The absolute value of the quadrupole coupling constant for both groups of Al27 nuclei is found to be 5173 ± 10 kc./sec. and the axial asymmetry parameter of the field gradient tensors at both the lattice positions is 0.698 ± 0.009. The two sets of principal axes are reflections of each other in the (010) plane which is consistent with the symmetry of the proposed crystal structure. The theoretical dependence of the spectrum line frequencies on the applied magnetic field is given for one group of Al27 nuclei and for one orientation of the crystal in fields up to 2000 gauss; the feasibility of checking this experimentally is discussed.


1990 ◽  
Vol 45 (11-12) ◽  
pp. 1248-1258 ◽  
Author(s):  
O. Böttcher ◽  
D. H. Sutter

AbstractHigh resolution zero field and Zeeman rotational spectra of 1 D-pyrazole have been studied by microwave Fourier-transform spectroscopy. The zero field hfs patterns allowed to improve the quadrupole coupling constants for both 14N nuclei. From the high field Zeeman multiplets the diagonal elements of the g-tensor were obtained as gaa= -0.1178(2),.gbb=-0.0762(2) and gcc = 0.0608 (2). The two independent components of the molecular magnetic susceptibility anisotropy in units of 10-6 erg G-2 mole- 1 are 2 ξaa - ξbb - ξcc= 52.69(32) and 2 ξbb - ξcc - ξaa = 39.32(29) were, a, b, c denote the molecular principal inertia axes. From these values the components of the molecular electric quadrupole moment tensor in units of 10-26 esu cm2 follow as Qaa = 5.84(22), Qbb= -0.58 (21) and Qcc= -5.27(38). Comparison with corresponding values for the undeuterated species leads to the complete tensors including their orientation with respect to the nuclear frame.


1998 ◽  
Vol 53 (6-7) ◽  
pp. 305-308
Author(s):  
M. Tanigaki ◽  
S. Takeda ◽  
K. Matsuta ◽  
Y. Matsumoto ◽  
T. Minamisono ◽  
...  

Abstract We studied the electric quadrupole interactions of Oxygen isotopes in a TiO2 single crystal. For 13O and 19O nuclei, quadrupole coupling constants were measured by the β-NMR technique, and for the 17O nucleus the FT-NMR technique was utilized. We synthesized a TiO2 single crystal which was enriched in 17O up to 5 atom % to observe NMR signals without any perturbations from impurities. Using the known quadrupole moment of 17O, EFGs at an O site in TiO2 and the quadrupole moments of 13O and 19O were determined.


1991 ◽  
Vol 69 (7) ◽  
pp. 808-812 ◽  
Author(s):  
J. Sagle ◽  
W. A. van Wijngaarden

Quantum beats arising from the hyperfine interaction were observed in the fluorescence produced when the 8D3/2, 9D3/2, and 10D3/2 states of 133Cs radiatively decayed to the 6P1/2 state. The period of the beats equals the reciprocal of the magnetic dipole coupling constant a since the 133Cs nucleus has a negligibly small electric quadrupole moment. The results are a = 3.95 ± 0.01, 2.38 ± 0.01, and 1.54 ± 0.02 MHz for the 8D3/2, 9D3/2, and 10D3/2 states, respectively.


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