AN INVESTIGATION OF THE NUCLEAR RESONANCE ABSORPTION SPECTRUM OF Al27 IN A SINGLE CRYSTAL OF EUCLASE

1955 ◽  
Vol 33 (6) ◽  
pp. 286-297 ◽  
Author(s):  
R. G. Eades
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Field Gradient ◽  
Resonance Spectrum ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Theoretical Dependence ◽  
Absolute Value ◽  
Principal Axes ◽  
Quadrupole Coupling

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.

NUCLEAR ELECTRIC QUADRUPOLE INTERACTION IN SINGLE CRYSTALS

1952 ◽  
Vol 30 (3) ◽  
pp. 270-289 ◽  
Author(s):  
G. M. Volkoff ◽  
H. E. Petch ◽  
D. W. L. Smellie
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Electric Quadrupole ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Gradient Tensor ◽  
Absolute Value ◽  
Principal Axes ◽  
Quadrupole Coupling

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.

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 ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Stable Isotope ◽  
Single Crystal ◽  
Field Gradient ◽  
Quadrupole Moment ◽  
Electric Quadrupole ◽  
Quadrupole Coupling Constant ◽  
Electric Quadrupole Moment ◽  
Coupling Constant ◽  
Quadrupole Coupling

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.

scholarly journals Electric Quadrupole Interaction of 20F in a KZnF3 Single Crystal

1976 ◽  
Vol 31 (11) ◽  
pp. 1298-1302 ◽  
Author(s):  
H. Ackermann ◽  
D. Dubbers ◽  
M. Grupp ◽  
P. Heitjans ◽  
H.-J. Stöckmann ◽  
...  
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Electric Quadrupole ◽  
Quadrupole Coupling Constant ◽  
Electric Quadrupole Interaction ◽  
Coupling Constant ◽  
Nmr Spectrum ◽  
Quadrupole Coupling ◽  
Γ Ray ◽  
Anisotropy Measurement

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.

Assignment and structural dependence of electric field gradients in anorthite and simple field gradient calculations in some aluminosilicates

1974 ◽  
Vol 140 (5-6) ◽  
Author(s):  
J. L. Staehli ◽  
D. Brinkmann
Keyword(s):  
Electric Field ◽  
Field Gradient ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Electric Field Gradients ◽  
Point Charge Model ◽  
Polarization Effects ◽  
Field Gradients ◽  
Charge Model ◽  
Quadrupole Coupling

AbstractThe electric field gradient tensors at theIt was found that the quadrupole coupling constant is correlated with the distortion of the coordination tetrahedra and that the simple point-charge model which neglects polarization effects is apt to yield quite satisfying results for very distorted tetrahedra.Similar results were obtained for the Al and Na sites in albite, NaAlSi

Über die chemische Bindung in Gold(I)-jodid

1966 ◽  
Vol 21 (11) ◽  
pp. 1025-1027 ◽  
Author(s):  
Paul Machmer
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Quadrupole Coupling ◽  
Constant E

The molecular electric field gradient (e qzz)610 at the nucleus of the gold isotope 197 is 42,7 · 1015 esu cm-3 according to our calculations. This value was used in calculating the quadrupole coupling constant in AuI and agreement is found with the experimental quadrupole coupling constant (e2 Q qzz)/h=508.296 MHz, if 50% s2-hybridisation and 21% ionicity are attributed to the gold-iodine bond. The ionicity in AuI is perhaps greater than in AuCl, as is indicated by the lower quadrupole coupling constant of Au197 in Aul.( (e2 Q qzz) /h=508,296 MHz in AuI, 514,150 MHz in AuCl 1.) This result is discussed with respect to the Townes-Dailey rule

A Theoretical Study of the Vibrational Dependence of the Nuclear Quadrupole Coupling Constants of some Diatomic Molecules

1994 ◽  
Vol 49 (1-2) ◽  
pp. 133-136
Author(s):  
E.A.C. Lucken
Keyword(s):  
Field Gradient ◽  
Theoretical Study ◽  
Diatomic Molecules ◽  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Nuclear Quadrupole Coupling Constant ◽  
Second Derivatives ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

Abstract The nuclear quadrupole coupling constant was calculated as a function of inter nuclear distance for nine quadrupolar nuclei in eight diatomic molecules by the STO 321G method. From the value of the field-gradient and its first and second derivatives the vibrational dependence of the coupling constants were calculated and shown to com pare satisfactorily with experiment. The behaviour of the field-gradient as a function of inter nuclear distance can in most cases be rationalized in terms of the field-gradient that will arise for the infinitely separated atoms.

Quadrupole coupling constant of12B in ZrB2 single crystal

1978 ◽  
Vol 4 (1-2) ◽  
pp. 224-225 ◽  
Author(s):  
T. Minamisono ◽  
S. Kogo ◽  
K. Okajima ◽  
K. Sugimoto
Keyword(s):  
Single Crystal ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Quadrupole Coupling

scholarly journals Hyperfine Structure in the Microwave Spectrum of Water

1957 ◽  
Vol 10 (2) ◽  
pp. 276 ◽  
Author(s):  
DW Posener
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Hyperfine Structure ◽  
Field Gradient ◽  
Quadrupole Coupling Constant ◽  
Microwave Spectrum ◽  
Coupling Constant ◽  
Quadrupole Coupling

Measurement of hyperfine structure in the microwave spectrum of D2O gives (eqQ)OD= + 353 � 4 kc/s for the quadrupole coupling constant of the deuteron in the direction of the OD bond, and the corresponding electric field gradient is .

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