Spectral Diffusion in Magnetic Resonance
Abstract
Electron spinspin interaction is discussed for the case of strong hyperfine broadening. The hyperfine interaction is represented by a resonance spectrum of width ∆ω and the electron interactions, which are taken to be dipolar, are treated by timedependent perturbation theory. A characteristic relaxation time for electron spins, τ_{s}=∆ω∆^{2}, is found, where ∆ is a measure of the strength of the dipolar interaction. The timedependent theory suggests a modification of the Bloch equations to give a phenomenological description of systems of this kind. Spinspin relaxation is represented by a term which gives diffusion of spin excitation through the resonance spectrum. Slow passage, rapid passage, and free relaxation are considered by using the modified equations.
 Publication:

Physical Review
 Pub Date:
 November 1956
 DOI:
 10.1103/PhysRev.104.584
 Bibcode:
 1956PhRv..104..584P