Pure Nuclear Electric Quadrupole Resonance in Impure Copper

1963 ◽  
Vol 130 (2) ◽  
pp. 589-595 ◽  
Author(s):  
Alfred G. Redfield
1972 ◽  
Vol 28 (15) ◽  
pp. 970-971 ◽  
Author(s):  
S. L. Segel ◽  
R. D. Heyding ◽  
E. F. W. Seymour

1965 ◽  
Vol 43 (12) ◽  
pp. 2262-2275 ◽  
Author(s):  
A. Manoogian ◽  
F. Holuj ◽  
J. W. Carswell

The electron spin resonance (ESR) spectrum of Fe+3 in spodumene, LiAl(SiO3)2, has been investigated at 24 kMc/sec. One set of five "allowed" transitions between the magnetic sublevels of the 6S5/2 ground state has been detected. The following values have been assigned to the parameters occurring in the spin Hamiltonian (eq. (1)) (bnm in gauss): gx = 2.0086 ± 50, gy = 2.0100 ± 50, gx ± 2.0046 ± 25, b20 = −1 430, b22 = −282, b40 = −20, b42 = 108, b44 = −182. Consideration of electric field gradients measured by methods of electric quadrupole resonance and of the orthorhombic parameters b20 and b22 did not lead to a unique assignment of the Fe+3 impurity to one of the two available cationic sites in spodumene.


1986 ◽  
Vol 41 (1-2) ◽  
pp. 453-462
Author(s):  
J. A. S. Smith

The importance of nuclear electric quadrupole interactions in chemistry, both present and future, depends very much on their power to resolve problems in electronic structure and molecular dynamics. Fortunately, the subject, by its very nature, is “multinuclear”; even if the ground state of a given nucleus is non-quadrupolar, there often exist excited nuclear states which are, an example being 19F, for which quadrupole coupling constants are now being published from angular correlation measurements. Other new techniques are constantly extending the range of the experiments, recent examples being the use of SQUID magnetometers to detect acoustic 121Sb and 123Sb quadrupole resonance in antimony metal and Fourier transform quadrupole resonance spectroscopy based on fast field cycling to measure 2H quadrupole interactions in powders. Recently, much work on quadrupole interactions in solids of half-integral spin nuclei such as 17O or 27Al has been pursued in two different ways; by quadrupole double resonance in natural abundance, and nuclear magnetic resonance in very high magnetic fields, for which enrichment of low-abundance nuclei such as 170 is often required. In the liquid phase, measurements are now sufficiently reliable for comparisons of changes in the nuclear electric quadrupole tensor from gas to liquid and solid phases to be made. The new methods of partial alignment of polar molecules in the liquid phase in strong electric fields, or magnetically anisotropic molecules in high magnetic fields, seem certain to contribute to these developments.


2008 ◽  
Vol 78 (12) ◽  
Author(s):  
David J. Cho ◽  
Feng Wang ◽  
Xiang Zhang ◽  
Y. Ron Shen

1975 ◽  
Vol 28 (7) ◽  
pp. 1439 ◽  
Author(s):  
KR Doolan ◽  
S Hacobian

Various monosubstituted and disubstituted benzenes were mixed in varying amounts with p-dichlorobenzene to form solid mixtures. The apparent spin-spin relaxation time, T*2, of the 35Cl nuclear quadrupole resonance of each of these mixtures was determined by a double pulsed super-regenerative oscillator (SRO) method which has been described previously.1 The SRO was operated in the logarithmic mode. The results show that electric quadrupole rather than magnetic dipole interactions are mainly responsible for the broadening that was observed for the 35Cl n.q.r. line of p-dichlorobenzene due to the impurities. The results also indicate that the para-disubstituted benzenes used formed uniform solid solutions with p-dichlorobenzene over the concentration range studied.


1991 ◽  
Vol 69 (7) ◽  
pp. 855-863 ◽  
Author(s):  
W. V. Prestwich ◽  
M. A. Islam ◽  
T. J. Kennett

A data set has been compiled consisting of 101 E2 strengths observed in neutron radiative capture. The E2 strength function is found to be consistent with a fifth power energy dependence and mass dependence characterized by a power of n = 1.87 ± 0.07. The observed strengths are on average consistent with those predicted on the basis of the giant quadrupole resonance. A reduction in strengths is apparent near mass regions 28, 82, and 157. Evidence is cited for the possible existence of a direct capture mechanism.


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