Off-specular reflection from flat interfaces with density or compositional fluctuations

Abstract

The reflection or scattering from a flat interface with density or compositional fluctuations has been investigated. An integral equation to relate the scattered intensities and the interface structure was proposed using a two-potential approach. The reflection geometry was taken into consideration explicitly in this derivation. This integral equation was applied to relate the off-specular scattering intensities to the interface structure in neutron or x-ray reflectivity measurements. Some numerical calculations based on model interfaces with certain structural features are conducted; and the results demonstrate the possibility of using the information from off-specular scattering to narrow the selections among the many model potentials or interface structures allowed by the specular reflectivity results.