Electron-energy-loss spectroscopy study of the electronic structure of a stable quasicrystal Al65Cu20Ru15

Electron-energy-loss spectra of a stable icosahedral quasicrystal Al65Cu20Ru15 have been obtained from single-quasicrystal areas 100-180 nm in diameter. The volume plasmon peak due to the sp valence electrons was observed at 17 .7eV with a full width at half-maximum of about 6 .5eV. Excitation spectra of Al L-shell electrons have a sharp onset (Fermi edge) and a small rise in intensity. The small rise in intensity corresponds to a small density of states near the Fermi level. These features indicate the presence of a pseudogap.