Abstract
Electron-energy-loss spectra of a stable decagonal quasicrystal Al70Ni20Rh10 have been obtained at electron incidences parallel and perpendicular to the decagonal axis on single-crystal areas of 180 nni diameter. Volume plasmon peaks appeared at about 17 eV for both incidences but showed full width at half-maximum values of 7.0 eV for the parallel incidence and 6.3 eV for the perpendicular incidence. Excitation spectra of Al L-shell electrons for both of the incidences showed a sharp onset (Fermi edge) at an energy higher by 0.1 eV than that of aluminium. The spectra showed a small rise in intensity at the onset. This small rise corresponds to a low density of states near the Ferrni level, showing the presence of a pseudogap. The origins of the high electrical resistivity and of the bonding nature of the quasicrystal are discussed.