Magneton Nuclear

The nuclear Zeeman effect is not a very strong interaction as compared to electric quadrupole splitting because of the relatively weak nuclear magneton. A field of B... 

Nuclear magnetic dipole moment of ground (g) and excited (e) state (in nuclear magnetons, n.m.)... 

The ground- and excited-state magnetic moments ji are tabulated as /ig = 0.09062(3) n.m. (nuclear magnetons, /i ) and jig, = 0.1549 n.m., respectively (see Table Properties of Isotopes Relevant to Mdssbauer Spectroscopy provided by courtesy of Professor J. G. Stevens, Mdssbauer Effect Data Center, cf. CD-ROM). Considering that nuclear magnetic moments are given by the relation p, = giPj I, the nuclear g factors for Ee with /g = 1/2 and 1 = 3/2 are gg = 0.09062 X 2 and ge = 0.1549 x 2/3. With these values and taken from... 

In Equation (6) ge is the electronic g tensor, yn is the nuclear g factor (dimensionless), fln is the nuclear magneton in erg/G (or J/T), In is the nuclear spin angular momentum operator, An is the electron-nuclear hyperfine tensor in Hz, and Qn (non-zero for fn > 1) is the quadrupole interaction tensor in Hz. The first two terms in the Hamiltonian are the electron and nuclear Zeeman interactions, respectively the third term is the electron-nuclear hyperfine interaction and the last term is the nuclear quadrupole interaction. For the usual systems with an odd number of unpaired electrons, the transition moment is finite only for a magnetic dipole moment operator oriented perpendicular to the static magnetic field direction. In an ESR resonator in which the sample is placed, the microwave magnetic field must be therefore perpendicular to the external static magnetic field. The selection rules for the electron spin transitions are given in Equation (7)... 

Here, /3 and / are constants known as the Bohr magneton and nuclear magneton, respectively g and gn are the electron and nuclear g factors a is the hyperfine coupling constant H is the external magnetic field while I and S are the nuclear and electron spin operators. The electronic g factor and the hyperfine constant are actually tensors, but for the hydrogen atom they may be treated, to a good approximation, as scalar quantities. 

If the unpaired electron is stabilized by resonance or is in a molecular orbital extending over the whole molecule, it must sometimes be detectable elsewhere than on the central carbon atom. The radical in which the central carbon atom is the isotope of mass 13 has been prepared. Whereas carbon 12 has a zero nuclear magnetic spin moment, carbon 13 has a nuclear pin of 0.5 and a magnetic moment of 0.7021 nuclear magnetons. The nuclear magnetic spin moment in an external field gives rise to a nuclear magnetic resonance absorption line, in much the same way as does the unpaired electron. If the unpaired electron... 

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