3D Level Resonant Photoemission in Ce and La Compounds

We have measured the 3d -photoemission of La and Ce at photon energies around their L3 absorption edges in LaPd and CePd. We have observed a modification of the photoemitted intensity of these deep core levels due to quantum interference between the direct photoemission channel and de-excitation of the core excited state, as first described by Fano. We discuss, in a qualitative way, the observed differences between La and Ce, as well as the possible role of quadrupolar transitions to the resonant process