Impurity-InducedgShift of Conduction Electrons

Abstract

A simple theory of the $g$ shift of conduction electrons induced by nonmagnetic impurities embedded in a metal is described. A single impurity atom is placed at the center of a large sphere containing a free-electron gas. The major contribution to the $g$ shift is obtained by calculating the change in the orbital angular momentum due to the spin-orbit interaction. Quite large $g$ shifts obtain when the spin-orbit interaction with the impurities is large, when the scattering phase shifts are not too small, when one or more partial waves go through a narrow resonance, or when the phase shifts change rapidly with energy without becoming large, and when the alloys are concentrated. Application of the theory to very dilute lithium alloys has revealed that the $g$ shifts are too small to be observable by means of conduction-electron spin resonance. This was confirmed by performing spin-resonance experiments on dilute Li-Zn, Li-Ag, and Li-Cd alloys. The theory presented here provides the extension of the theory of the $g$ factor of atomic electrons to the case of electrons in the continuum states.