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.

Hydrogen Bond Studies

1977 ◽  
Vol 32 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Bo Berglund ◽  
Jörgen Tegenfeldt
Keyword(s):  
Asymmetry Parameter ◽  
Room Temperature ◽  
Sodium Perchlorate ◽  
Quadrupole Coupling Constant ◽  
Water Molecules ◽  
Coupling Constant ◽  
Nmr Spectrum ◽  
Quadrupole Coupling ◽  
Constant E ◽  
The Difference

The quadrupole splittings in the deuterium NMR spectrum from single crystals of deuterated sodium Perchlorate monohydrate, NaClO4-D2O, have been measured at 25 °C and - 55 °C. At room temperature, the 180° flip frequency of the D2O molecules is large compared to the difference between the splittings for the two deuterons. The average quadrupole coupling constant (e2 q Q/h) and asymmetry parameter η are 134.1(4) kHz and 0.621(5), respectively. At -55 °C, the electric field gradient tensors for each of the two deuterons were observed corresponding to slowly flipping water molecules, and e2 qQ/h and η for the two deuterons are 231.5(6) and 226.7(6) kHz and 0.196(4) and 0.195(5), respectively. The results indicate that the hydrogen positions in NaClO4-H2O are dynamically disordered

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.

Electric Quadrupole Moment of the 14N Nucleus Determined by ab initio Cl Calculation on NH3

1986 ◽  
Vol 41 (1-2) ◽  
pp. 163-165 ◽  
Author(s):  
Tae-Kyu Ha
Keyword(s):  
Electric Field Gradient ◽  
Ab Initio ◽  
Electric Quadrupole ◽  
Quadrupole Coupling Constant ◽  
Basis Set ◽  
Electric Quadrupole Moment ◽  
Coupling Constant ◽  
Hartree Fock ◽  
Quadrupole Coupling ◽  
Constant E

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.

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.

Temperature and Pressure Dependence of 209Bi Nuclear Quadrupole Resonance in BiCl3

1972 ◽  
Vol 50 (16) ◽  
pp. 2586-2590 ◽  
Author(s):  
G. C. Gillies ◽  
R. J. C. Brown
Keyword(s):  
Pressure Dependence ◽  
Room Temperature ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Nuclear Quadrupole Coupling Constant ◽  
Quadrupole Coupling ◽  
Quadrupole Resonance ◽  
Temperature And Pressure ◽  
Nuclear Quadrupole ◽  
Crystal Volume

The temperature and pressure dependence of the 209Bi nuclear quadrupole coupling constant and asymmetry parameter in solid BiCl3 have been measured near room temperature. It is not possible to account for the results on the basis of the conventional theory in which the field gradient parameters depend only on the crystal volume.

121Sb NMR and SCF-MS-Xα Studies of Quadrupole Interaction and The Electronic Structure of Mixed-Valence Compound, Cs2SbCl6

1996 ◽  
Vol 51 (5-6) ◽  
pp. 672-676 ◽  
Author(s):  
Takahiro Ueda ◽  
Nobuo Nakamura
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Ground State ◽  
Mixed Valence ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Nmr Spectrum ◽  
Quadrupole Coupling ◽  
Mixed Valence Compound ◽  
Complex Anions

Cs2SbCl6 is known as a typical mixed-valence compound. It crystallizes into a tetragonal space group I41/amd and contains two different complex anions, Sb(III)Cl3-6 and Sb(V)Cl-6 . The dark blue color of this compound has been considered to originate from a charge transfer between the above two anions. In order to study the electronic structure of these complex anions and the existence of charge transfer between them we measured the 121Sb NMR spectrum and carried out molecular orbital calculations on the electronic states of these anions. The 121Sb NMR spectrum consists of two peaks at 0 and 30 kHz which can be assigned to the central transition of 121Sb in Sb(V)Cl-6 and Sb(III)Cl3-6 , respectively. The line shape analyses of the spectra led to nuclear quadrupole coupling constants of nearly zero for Sb(V)Cl-6 and 4.9 ± 0.5 MHz for Sb(III)Cl3-6 at room temperature. The quadrupole coupling constant of 121Sb(III) decreases steadily on heating. The calculations of the electronic ground state energies of both anions were calculated by the MS-Xα molecular orbital method. The calculated charge-transfer band from the A1g state of Sb(III)Cl3-6 to the A1g state of Sb(V)Cl-6 appears at 610 nm and can account for the experimental electronic spectrum, the calculated quadrupole coupling constant in Sb(III)Cl3-6 however is far larger than the experimental one. The contribution of the charge-transferred state to the ground state is negligible and so the temperature dependence of the quadrupole coupling constant of 121Sb(III) is attributed to an anisotropic thermal expansion of the compound.

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.

TEMPERATURE DEPENDENCE OF THE PURE NUCLEAR QUADRUPOLE RESONANCE FREQUENCY IN KClO3

1960 ◽  
Vol 38 (11) ◽  
pp. 1397-1405 ◽  
Author(s):  
J. Vanier
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Quadrupole Coupling Constant ◽  
Nuclear Quadrupole Resonance Frequency ◽  
Lattice Vibrations ◽  
Coupling Constant ◽  
Air Temperatures ◽  
Quadrupole Coupling ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

The resonant frequency of the Cl35 nuclear quadrupole in KClO3 has been measured as a function of temperature in the range 15 deg;K to 77 deg;K; previous work between 77 deg;K and room temperature has been confirmed. Comparison has been made with Bayer's theory based on lattice vibrations and agreement is excellent. The ratio of the quadrupole coupling constant eQqzz of the two isotopes (Cl35 and CI37) has been measured at room and liquid air temperatures; significant changes have been observed in the measurements. Finally the possibility of using this temperature dependence as the basis of a sensitive thermometer has been studied; the accuracy of such a thermometer would be ±0.005 deg;K at 60 deg;K and ±0.05 deg;K at 20 deg;K.

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