Interactions arising from nuclear magnetic and electric moments

Interactions arising from nuclear magnetic and electric moments... 

Nuclear relaxation is caused by interaction between the nuclear magnetization M and small incoherent magnetic fields which arise from random Brownian motions of molecules (Abragam, 1961 Farrar and Becker, 1971 Becker, 1974). In the case of quadrupolar nuclei, electrical fields interact with the electric quadrupole moment of the nucleus. The fluctuating fields can arise from a number of processes, including (1) magnetic dipole-dipole interaction, (2) electric quadrupole interaction, (3) scalar coupling, (4) spin-rotation interaction, and (5) chemical shift anisotropy. 

Equation (3.159) describes the spin-orbit coupling, the two terms involving the nuclear and electronic potentials respectively. It is interesting to note that these terms arise from the interaction between the electron spin magnetic moment and the effective magnetic field created by the passage of the electron through the electric field created by the other particles. 

An important class of properties arise from multipolar expansions of the interaction of nuclear moments with the electric and magnetic fields set up by surrounding electrons and nuclei. Restrictions apply to the possible nuclear moments 2 [93]. In general I < 21, where I is the nuclear spin. Furthermore, electric (magnetic) moments are restricted to even(odd) values of /. The lowest nuclear electric multipole is accordingly the electric quadmpole moment... 

This interaction is between the nuclear spin and the molecular magnetic moment which arises from the angular momentum of the rotating molecule. When the molecule remains in a given angular momentum state, its electronic structure produces a constant electric current and this would not lead to... 

In part the interest arises from the fact that the spectroscopic state 87/2 is the same for the atom, 4f 6s as for the divalent ion, 4f . The former has been studied by atomic beam triple resonance (Sandars and Woodgate 1960, Evans et al. 1965), and the latter by ENDOR (Baker and Williams 1962) in Cap2, an environment with cubic symmetry. For a half-filled shell, with no orbital momentum and a spherical distribution of electron spin moment with zero density at the nucleus, both the magnetic dipole and electric quadrupole interactions should be zero. Experimentally, they are small compared with the values for other odd-proton lanthanide isotopes with comparable nuclear moments, for which the hyperfine... 

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