Resonant magnetic X-ray scattering at the lanthanide M5 edges

Magnetic soft X-ray scattering at the Ho M5 resonance was characterized using thin films, thus reducing the effect of the strong photon absorption. Magnetic scattering factors are found to be as large as 200r0 at resonance, while the effective probing depth of the X-rays at the resonance maximum is of the order of 30A at 2θ=25-bar . The huge enhancement of magnetic scattering allows one to study ultrathin Ho films, which is exploited to investigate the thickness dependence of the Neel temperature in these long-period antiferromagnets. The tunable X-ray penetration depth across the resonance can be used for magnetic depth profiling, e.g. to study the depth-dependent growth of antiferromagnetic domains across the ferromagnetic/antiferromagnetic phase transition in Dy metal films