Saturation and self-absorption effects in the angle-dependent 2p3d resonant inelastic X-ray scattering spectra of Co.

Angle-dependent 2p3d resonant inelastic X-ray scattering spectra of a LaCoO single crystal and a 55 nm LaCoO film on a SrTiO substrate are presented. Theoretical calculation shows that, with ∼20 meV resolved Co 2p3d resonant inelastic X-ray scattering (RIXS), the excited states of the isotropic A(O) ground state are split by 3d spin-orbit coupling, which can be distinguished via their angular dependence. However, strong self-absorption and saturation effects distort the spectra of the LaCoO single crystal and limit the observation of small angular dependence. In contrast, the RIXS on 55 nm LaCoO shows less self-absorption effects and preserves the angular dependence of the excited states.