scholarly journals The effects of librations on the 13C chemical shift and 2H electric field gradient tensors in β-calcium formate

2000 ◽  
Vol 113 (24) ◽  
pp. 11187-11193 ◽  
Author(s):  
Kevin J. Hallock ◽  
Dong Kuk Lee ◽  
A. Ramamoorthy
Keyword(s):  
Chemical Shift ◽  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
13C Chemical Shift ◽  
Calcium Formate

Cesium-133 NMR Study of CsCd(SCN)3:  Relative Orientation of the Chemical Shift and Electric Field Gradient Tensors

1997 ◽  
Vol 101 (19) ◽  
pp. 3727-3733 ◽  
Author(s):  
Scott Kroeker ◽  
Klaus Eichele ◽  
Roderick E. Wasylishen ◽  
James F. Britten
Keyword(s):  
Chemical Shift ◽  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Relative Orientation ◽  
Nmr Study

Quadrupole Moments of the 40Ca Core Plus One Nucleon Nuclei 41Sc and 41Ca

2002 ◽  
Vol 57 (6-7) ◽  
pp. 595-598
Author(s):  
T. Minamisono ◽  
K. Matsuta ◽  
K. Minamisono ◽  
S. Kudo ◽  
M. Ogura ◽  
...  
Keyword(s):  
Finite Element ◽  
Chemical Shift ◽  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
High Field ◽  
Quadrupole Moments ◽  
Hartree Fock ◽  
Hyperfine Constants ◽  
Anisotropic Chemical Shift

The electric-field-gradient (EFG) and anisotropic chemical shift of 45Sc(Iπ = 7/2- , stable) in TiO2 crystal were determined by detecting the FT-NMR of 45Sc(0.5 atm% of Ti in TiO2) doped in TiO2 crystal at a high field of 7.0 T and 9.4 T. Using the EFG, an old β-NQR spectrum of 41Sc was reanalyzed to obtain (41Sc)/ which was combined with the renewed (45Sc) = -(23.6 0.2) fm2 to obtain (41Sc; Iπ= 7/2- , T1/2 = 0.596 s) = (15.6±0.3) fm2. Also the atomic EFG in Ca was recalculated, using a finite-element multi configuration Hartree-Fock method to renew Q(43Ca). Finally using the known hyperfine constants of 41Ca, the (41Ca) value has been renewed

93Nb Solid State NMR of High Surface Area Niobium Oxides

2006 ◽  
Vol 984 ◽  
Author(s):  
Luis Smith ◽  
Xuefeng Wang
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Solid State Nmr ◽  
High Surface ◽  
Chemical Shift Anisotropy ◽  
Material Surface ◽  
Alkali Cations

AbstractThe local environment of niobium in oxides reflects the perturbations in bond strength that affect the acidity of oxygen atoms in the structure. To understand the relationship between metal environment and properties, 93Nb solid state NMR has been used to measure the electric field gradient and chemical shift anisotropy for layered niobates with either alkali cations or protons at the material surface. In order to determine these parameters, a variety of techniques have been applied to extract information for the multiple environments located in these oxides. Variable offset cumulative echo spectra were collected on static samples at multiple magnetic fields, 4.7 T, 9.4 T and 14.1 T. RAPT enhanced QPASS data were collected at 9.4 T to extract quadrupolar-coupling information without the influence of chemical shift anisotropy. Data from KCa2Nb3O10 and an acid exchanged form was collected and two distinct quadrupolar environments were observed. Acid exchange altered the isotropic chemical shift but did not significantly affect the electric field gradient or the chemical shift anisotropy.

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