Nuclear Quadrupole Coupling, Knight Shift, and Spin-Lattice Relaxation Time in Beryllium Metal

1967 ◽  
Vol 157 (3) ◽  
pp. 510-515 ◽  
Author(s):  
D. E. Barnaal ◽  
R. G. Barnes ◽  
B. R. McCart ◽  
L. W. Mohn ◽  
D. R. Torgeson
Keyword(s):  
Relaxation Time ◽  
Knight Shift ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Beryllium Metal

17O Quadrupole Dips in Ammonium Persulphate

1994 ◽  
Vol 49 (1-2) ◽  
pp. 345-350 ◽  
Author(s):  
N. F. Peirson ◽  
J. A. S. Smith ◽  
D. Stephenson
Keyword(s):  
Relaxation Time ◽  
Lattice Relaxation ◽  
Quadrupole Coupling Constant ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Ammonium Persulphate ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Resonance Frequencies ◽  
Quadrupole Coupling

Abstract The magnetic field dependence of the 1H spin-lattice relaxation time in ammonium persulphate shows pronounced minima near the 1H magnetic resonance frequencies of 1,200 and 2,200 kHz. These are interpreted in terms of a model involving cross-relaxation between 1H in the NH4 ion and 17O in natural abundance in the S2O2-8 ions, the latter having a much shorter spin-lattice relaxation time. A theoretical analysis of the shape of the minima is used to derive values for the 17O quadrupole parameters. This analysis results in best estimate values for the quadrupole coupling constant of 6.75 (± 0.05) MHz and an asymmetry of 0.30 (± 0.02). Such values are indicative o f O-H hydrogen bonding and suggest the S2O2-8 ion is not undergoing rapid reorientation at temperatures below 320 K.

scholarly journals Pressure Dependence of the Chlorine NQR in Three Solid Chloro Anisoles

2001 ◽  
Vol 56 (11) ◽  
pp. 764-772 ◽  
Author(s):  
K. S. Suresh ◽  
K. P. Ramesh ◽  
C. Raghavendra Rao ◽  
J. Ramakrishna
Keyword(s):  
Relaxation Time ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Linear Variation ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Temperature Coefficients ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

Abstract The 35C1 Nuclear Quadrupole Resonance (NQR) frequency (VQ) and spin lattice relaxation time (T1) in the three anisoles 2,3,4-trichloroanisole, 2,3,6-trichloroanisole and 3,5-dichloroanisole have been measured as a function of pressure upto 5.1 kbar at 300 K, and the data have been analysed to estimate the temperature coefficients of the NQR frequency at constant volume. All the three com­ pounds show a non linear variation of the NQR frequency with pressure, the rate of which is positive and decreases with increasing pressure. In case of 3,5-dichloroanisole the value becomes negative in the higher range of pressure studied. The spin lattice relaxation time T1 in all the three compounds shows a weak dependence on pressure, indicating that the relaxation is mainly due to the torsional motions.

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