Resonant soft X-ray scattering for simultaneous determination of magnetic order and Hall effect in a ferrimagnetic film (Invited Paper)

Recently, the determination of the topological Hall effect has caused some controversy in the field of spintronics due to the validity of subtracting a magnetization-scaled anomalous Hall component from an experimentally measured Hall resistance. Often the underlying magnetic texture and topology are determined ex-situ of the Hall measurement which can lead to experimental error. Here we report the simultaneous determination of the magnetic texture and Hall effect in a ferrimagnetic FeGd thin film using resonant soft X-ray scattering with in-situ magneto-electrical transport. We find the largest departure of the Hall component at the 6-fold symmetric scattering of the dipole skyrmion state but also an additional smaller feature of opposite sign at higher fields where we observe diffuse scattering just before saturation. We attribute this additional feature to a skew scattering term arising from isolated skyrmions close to saturation.