SPIN-FLIP SCATTERING OF LOW-ENERGY ELECTRONS FROM MAGNETIC-SURFACES NEAR THEIR ORDERING TEMPERATURE - APPLICATION TO CR(110)

We examine the theory of spin-flip scattering of low-energy electrons from magnetic surfaces near their ordering temperature, to inquire if the spin-flip contribution to the diffuse background can be used to explore the nature of spin fluctuations near the surface, in this temperature regime. The spin-flip contribution to the diffuse background is related to equal-time correlation functions, which contain information about the amplitude of the near-surface spin fluctuations. These are calculated within the framework of Landau-Ginzburg theory, and their properties explored for various cases. The results are combined with a multiple-scattering-based description of the excitation process, to generate quantitative predictions for the antiferromagnetic Cr(110) surface. The calculations enable us to isolate particular scattering geometries which should be particularly favorable for the observation of surface spin fluctuations near the Néel temperature. © 1994 The American Physical Society.