Soft x-ray ptychography studies of nanoscale magnetic and structural correlations in thin SmCo 5 films
High spatial resolution magnetic x-ray spectromicroscopy at x-ray photon energies near the cobalt L 3 resonance was applied to probe an amorphous 50 nm thin SmCo 5 film prepared by off-axis pulsed laser deposition onto an x-ray transparent 200 nm thin Si 3 N 4 membrane. Alternating gradient magnetometry shows a strong in-plane anisotropy and an only weak perpendicular magnetic anisotropy, which is confirmed by magnetic transmission soft x-ray microscopy images showing over a field of view of 10 μm a primarily stripe-like domain pattern but with local labyrinth-like domains. Soft x-ray ptychography in amplitude and phase contrast was used to identify and characterize local magnetic and structural features over a field of view of 1 μm with a spatial resolution of about 10 nm. There, the magnetic labyrinth domain patterns are accompanied by nanoscale structural inclusions that are primarily located in close proximity to the magnetic domain walls. In conclusion, our analysis suggests that these inclusions are nanocrystalline Sm 2 Co 17 phases with nominally in-plane magnetic anisotropy.