XAS and XMCD study of $3d$-$4d$ hybridization in Ni/Pd films

X-ray Absorption Spectroscopy (XAS) and X-ray Magnetic Circular Dichroism (XMCD) measurements at the Ni $L_{\rm 3;2}$- and Pd $M_{\rm 3;2}$-edge were carried out to reveal changes in intrinsic electronic and magnetic structures of Ni-Pd films prepared in various configurations, such as Ni, Ni/Pd, Ni/Pd- multilayer, and NiPd-alloy. All films were grown by $in~situ$ e- beam evaporation system in the measurement chamber. The satellite structures (6 eV and 4 eV) of bulk Ni, which are present in XAS and XMCD spectra, disappear as portion of Ni/Pd interface increases such as multilayer, while XMCD signal of Pd became enhanced. Effects of the increased portion of Ni/Pd interface were also revealed in NiPd alloy film. The findings strongly imply that increased intermixing at the interface gives rise to the $d$-electron charge transfer at the interface and results in the modified orbital moments, which is a direct evidence for a close relation between the modified magnetic property and the interfacial $3d$-$4d$ hybridization in Ni-Pd films.