Spin-Lattice Linewidths for EPR in Multilevel Systems

Abstract

The magnetic relaxation of an isolated moment via contact coupling to conduction-electron spins is considered for the case where the splitting scheme of the moment shows an effective-spin doublet plus other levels. Relaxation transitions proceeding via these other levels are considered, and it is shown that they produce significant deviations from the proportional-to-temperature linewidth obtained by considering only direct transitions within the doublet. Some results for phonon processes are also given.