General treatment of off-specular resonant soft X-ray magnetic scattering using the distorted-wave Born approximation: Numerical algorithm and experimental studies with hybrid chiral domain structures

We present a numerical algorithm for the simulation of resonant X-ray magnetic scattering in reflection geometry for an arbitrary three-dimensional magnetization distribution over a multilayer sample utilizing the distorted-wave Born approximation. Our approach takes the medium boundary matrix approach for specular reflection, and the Born approximation typically used for off-specular reflection, combines the two, and adds the contribution from transmission through the sample before and after a reflection event. The algorithm is then tested on experimental data from an Al2O3/Co/Pt multilayer sample with hybrid Neél/Bloch/Neél domain walls at incidence angles at and near multilayer Bragg angles, and photon energies near the Co L3 absorption edge, achieving high levels of agreement with experimental data. Incorporating the transmission components into the algorithm was found to explain the dichroism observed in scattering from Bloch-type domain walls, and uncovered the likely importance of diffuse scattering in transmission from the polycrystalline grain walls along the optical path of the x rays in the sample- A theme which deserves further investigation.