Electronic distributions in quasicrystalline Al65Cu20Ru15 alloy

Occupied and unoccupied electronic distributions of quasicrystalline Al65Cu20Ru15 have been studied mainly using soft-x-ray emission and absorption spectroscopy measurements. The partial distributions are adjusted in the binding energy scale in order to gain insight into the electronic interactions in this material. Interaction between Al states and Ru 4d states near the Fermi level and between Al and Cu 3d states in the middle of the occupied band is shown. At the Fermi level a significant pseudo-gap is observed in the Al 3p and 3s-d distributions. In the unoccupied band, the Ru and Cu d-s-like states are in interaction with the Al p states. The Ru and Cu states retain a slight d-like character at the energies of the conduction edges that suggests faint charge transfer to Ru atoms. Far from the Fermi level, the Ru and Cu states are strongly hybridized to s states. Adjustment of Al 3p and Al p distributions at the same intensity at the Fermi level points to a significant low intensity of the density of Al p conduction states over a few electronvolts from the Fermi level.