Ferromagnetic interlayer coupling in C60–Co compound/Ni bilayer structure

X-ray magnetic circular dichroism (XMCD) spectroscopy was employed to investigate the electronic and magnetic structures of the bilayers of a C60–Co compound and Ni. A few–several nm thick C60–Co compound layers on the Ni(1 1 1) surface are found to show intense XMCD signals attributed to the localized Co d-spins only with the remanent magnetization of Ni layer. It is suggested that the region of the C60–Co compound within 3 nm from the interface is ferromagnetically coupled with Ni due to the indirect exchange interaction mediated by C60, probably relevant to the interlayer charge transfer.