Magnetic moments, interaction

For a molecule with several nuclei with nonzero spin, magnetic moment interacts with B0 and the Hamiltonian is each nuclear... 

NMR is not an explicitly surface - sensitive technique, but NMR data on large surface area samples (> 1 m2) have provided useful data on molecular adsorption geometries. The nucleus magnetic moment interacts with an externally applied magnetic field and provides spectra highly dependent on the nuclear environment of the sample. The signal intensity is directly proportional to the concentration of the active species. This method is limited to the analysis of magnetically active nuclei. 

Electron orbital angular magnetic moment)-(electron orbital magnetic moment) interaction energy ... 

This magnetic moment interacts with the applied magnetic field. In classical terms the energy of the interaction between the magnetic moment (p) and the field (B) is described by... 

This corresponds to the principle of minimal coupling, according to which the interaction with a magnetic field is described by replacing in the Hamiltonian operator the canonical momentum p by the kinetic momentum 11 = p — f A(x). Other types of external-field interactions include scalar or pseudoscalar fields and anomalous magnetic moment interactions. The classification of external fields rests on the behavior of the Dirac equation rmder Lorentz transformations. A brief description of these potential matrices will be given below. 

Here the first line represents the influence of the magnetic field only, the second and third line the magnetic field-nuclear magnetic moments interaction, the fourth line the magnetic field-electronic magnetic moment interaction and the last one the electronic-nuclear magnetic moments interaction (it is a new term). 

These two aspects of the electron spin, that of an internal dynamical variable introduced to satisfy a symmetry requirement and that related to an intrinsic magnetic moment interacting with an external field, were elucidated by Dirac from his quantum-relativistic equation. But it also yielded an electron moving at the speed of light ... 

Finally, the nuclear magnetic moment interaction ( coupling ) will be considered. 

The electronic spin-spin terms Hss) i e., the corresponding spin magnetic moment interactions, related to the term Hs in the Breit Hamiltonian... 

The through space dipole-dipole nuclear magnetic moment interaction (the nuclear analog of the Hs term in the Breit Hamiltonian) 5Za[Pg.768]

Since the ESR spectrum results from a change in the electron s spin state (with or against the field), it might be supposed that all ESR spectra would consist of a single transition. Fortunately, as with NMR, this is not the case. Bound unpaired electrons are very sensitive to the nuclei around them, through magnetic moment interaction, shown in Figure 3.82. 

The hyperfine and spin-orbit interactions are both magnetic moment interactions involving the electron spin, but the hyperfine energy is typically less than 10 times the spin-orbit energy. Is this consistent with the correspondence principle ... 

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