Direct Evidence of the Role of Hybridization in the X-Ray Magnetic Circular Dichroism of α -Ce

We present an x-ray magnetic circular dichroism (XMCD) study of a [Ce(10 {})/Fe(30 {})] multilayer performed at the Ce-M4,5 absorption edges. In this system the Ce-$4f$ electrons are strongly hybridized with the valence band. XMCD experiments show that they carry an ordered magnetic moment. The differences of the shape of the XMCD signals of a typical γ-like compound (CeCuSi) and of the Ce/Fe multilayer highlight the role of hybridization in determining the ground state of cerium atoms in the multilayer, which results in a mixing of J=5/2 and J=7/2 coupled states.