Magnetic exchange splitting of a quasi two-dimensional hexagonal close packed layer of cobalt

Abstract In order to study the magnetic behaviour of one monolayer of a magnetic material we have performed angle-resolved photoemission measurements of the electronic structure of Co deposited on top of a clean well ordered Cu(111) surface using synchrotron radiation. The deposition of Co has been followed by Low Energy Electron Diffraction and Auger Spectroscopy and results in a well ordered layer-by-layer growth of Co. The results for different photon energies indicate that the interaction between the d-orbitals of Co and Cu is weak. The spectrum corresponding to k ∥ =0 for one layer of Co has the same exchange splitting induced three peak structure of the spectrum corresponding to a Co single crystal (0001) surface. The magnetic exchange splitting at the centre of the two-dimensional Brillouin zone (Γ point) is ∼0.7 eV whereas at the corner ( K point) it is ∼0.5 eV.