Resonant soft X-ray and extreme ultraviolet magnetic scattering in nanostructured magnetic materials: Fundamentals and directions

Highlights: ► We review the theory or resonant soft X-ray magnetic scattering. ► The interplay of resonant charge and magnetic scattering is emphasized. ► Resolving in-plane heterogeneity in thin films in transmission geometry is considered. ► Resolving in-depth heterogeneity in reflection geometry is considered. ► We review practical considerations for planning and interpreting measurements. -- Abstract: Theoretical and practical aspects of resonant magnetic and charge scattering in the soft X-ray and extreme ultraviolet spectral ranges are reviewed. Intensity-only measurements are considered because they are more efficient than polarization-resolving measurements. Two very different approaches are discussed and compared; transmission small-angle scattering described by a simple kinematical scattering model and specular reflection described by more complex yet standard magneto-optical formalisms. In both cases the scattered intensity is seen to contain distinct terms resulting from pure-charge scattering, pure-magnetic scattering, and charge-magnetic cross-terms, and emphasis is placed on distinguishing these contributions via their energy spectra and its dependence on incident polarization. Combined with measurements vs. scattering vector q, both approaches provide significant capability to resolve magnetic and chemical structure down to nanometer length scales. The role of and need for modeling to obtain reliable information from data is discussed, as are current directions and opportunities