Magnetic hyperfine interactions principles

The underlying physics and analysis of Mossbauer spectra have been explained in detail in Chap. 4. In that chapter, the principles of how a spectrum is parameterized in terms of spin-Hamiltonian (SH) parameters and the physical origin of these SH parameters have been clarified. Many Mossbauer studies, mainly for Fe, have been performed and there is a large body of experimental data concerning electric-and magnetic-hyperfine interactions that is accessible through the Mossbauer Effect Database. 

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 ... 

F.6.4.1. Introduction. If the surface-related phenomena are negligible, the electronic spins in the particle will fluctuate in unison (see Section D.3.1), and the orientation of the hyperfine field will fluctuate like the orientation of the magnetic moment of the particle m. The Mossbauer nucleus senses the relaxation of m via the hyperfine interaction and thus the Mossbauer spectrum can, in principle, be influenced by all the trajectories of m. 

Most radicals contain one or more atoms with magnetic nuclei, so that the unpaired electron interacts not only with the applied field but also with internal fields. This results in the splitting of the resonance absorption into two or more components. The principles of hyperfine splitting have been described (Symons, 1963). Interaction with a nucleus of spin I splits the resonance into (2/4-1) components e.g. the e.s.r. spectrum of 3... 

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