Theory of inelastic electron scattering from antiferromagnetic NiO: Surface and bulk effects

Abstract

A simple one-magnon formalism for the calculation of the inelastic exchange scattering of electrons from antiferromagnets is presented. Exponential attenuation of the electron beam in the bulk due to Coulomb scattering is introduced phenomenologically. In the limit of infinite penetration length, the exact bulk results are obtained. For finite penetration lengths, surface modes contribute to the process. The formalism is applied to the ferromagnetic (111) surface of antiferromagnetic NiO. For realistic values of the beam penetration, our results indicate that both surface and bulk magnons contribute to the electron dynamic scattering function and should be easily resolved over most of the surface Brillouin zone.