Investigating magnetic proximity effects in PdCo using polarized neutron and X-ray reflectometry

We report on a polarized neutron reflectivity investigation of the magnetic proximity effect in PdCo bilayer. Magnetization of individual layers is measured independently, and individual hysteresis loop is inferred. The proximity effect in Si < 100 > /Pd_x/Co_y samples is explored as a function of layer thickness. Grazing incidence X-ray diffraction measurements were carried out to check the purity and the structure of the samples. Polarized neutron reflectometry was used to evaluate the magnetic moment. The measurements have shown a good structural quality and a surface roughness less than 0.5 nm. A net magnetization was observed from the splitting of the non-spin flip reflectivity curves. The measured Pd magnetic moment varied from 0.012 to 0.031 μ_B/Pd atom. In spite of the low values found, we have demonstrated the existence of a correlation between Pd magnetic moment and the thickness ratio t(Pd)/t(Co).