Coupled Local-Moment—Conduction-Electron Bloch Equations for Cubic and Axial Symmetry

Coupled local-moment---conduction-electron Bloch equations suitable for interpreting electron-spin-resonance experiments in dilute magnetic alloys are derived, thus extending Hasegawa's early work. The g value of the local-moment impurities is not assumed equal to the conduction-electron g value, and the form of the diffusion- and drift-current contributions to the Bloch equation for electrons is determined. Impurities of arbitrary spin at sites of cubic symmetry are studied in detail (e.g., Cu: Mn and Ag: Er) as are impurities of spin S=1/2 at sites of axial symmetry (e.g., Mg: Er). Simple arguments are given to demonstrate that relaxation is toward instantaneous local equilibrium.