Data representations of Zeeman spatial beam splitting in polarized neutron reflectometry

Abstract

The different Zeeman beam-splitting effects in neutron reflectivity experiments in reflection and refraction are discussed. Different possible representations of the experimental Zeeman splitting data in various coordinate systems are investigated. Some of these representations are useful to unambiguously identify the off-specular splitting arising from Zeeman energy and discriminate it from the usual diffuse scattering. Some representations are more suited for the direct extraction of quantitative information about the systems by using the Zeeman splitting effect. The Zeeman splitting can thus be used as a tool rather than being treated as a parasitic effect. Parameters such as the optical and magnetic potentials of buried layers can be directly extracted. The magnetic induction in demagnetized samples can also be probed. These representative characteristics are illustrated by experimental data measured on different systems. In thick AlSiFe films (20 µm), the magnetic induction is determined at the top and bottom interfaces. In thin Co layers (250 nm), the magnetic induction of ferromagnetic domains in the demagnetized state is evaluated.