A Simple Derivation of the Bloch Equations for Localized Moment E.S.R. in Metals in the Presence of Anisotropy

Abstract

A density-matrix approach is used to derive the coupled Bloch equations for the electron spin resonance of localized moments and conduction electrons in metals, including anisotropy fields acting on the local moments. The equations agree with those obtained elsewhere by more sophisticated many-body techniques. In particular, it is demonstrated explicitly that relaxation proceeds towards instantaneous equilibrium.