Electronic structure studies of the buried Ni layer in a Cu/Ni/Cu multilayer by resonant photoemission at the Ni L3 edge

Abstract

The electronic structure of the buried Ni layer in a Cu 20 Å/Ni 50 Å/Cu 2000 Å/Si(100) multilayer system has been studied by means of resonant photoemission spectroscopy at the Ni L3 (2p3/2→3d) absorption edge. Information on the electronic structure was extracted by utilizing the difference spectrum between the on- and off-resonance spectra as well as the relatively larger escape depth of the valence band photoelectron at the excitation energy of the Ni L3 absorption edge compared to that at 3p→3d edge. The extracted 3d band of the intervening Ni layer shows an enhanced structure around 2–4 eV compared to that of pure Ni metal, and is attributed to the hybridization effect with Cu. Application of this method in combination with circularly polarized light could provide opportunities for spin sensitive experiments on more realistic magnetic material systems.