Resolving magnetic and chemical correlations in CoPtCr films using soft X-ray resonant scattering

Resonant small-angle scattering at the 2p levels of 3d transition elements strongly enhances scattering from both magnetic and chemical structure in the plane of thin films, as recently demonstrated for Co/Pt multilayers having perpendicular anisotropy. Here this resonant enhancement is demonstrated for CoPtCr films having in-plane magnetic anisotropy. A simple formalism describing the spectral dependence of the kinematical scattering provides a means to distinguish between magnetic and charge scattering and to probe the chemical segregation processes yielding charge scattering, thereby providing new information about this structure. It is found that correlation lengths of magnetic scattering are roughly 5 times larger than those for chemical scattering in the as-deposited CoPtCr film studied, consistent with significant exchange-coupling between polycrystalline grains.