Abstract
Al L-shell excitation spectra of Al-based quasicrystals of Al75Cu15V10, Al73Co27 and Al70Pd20Mn10 and related crystals were obtained from specified single crystalline areas by using a high energy-resolution electron energy-loss spectroscopy microscope. Intensity distributions of the spectra of not only the quasicrystalline materials but also related crystalline materials showed a presence of pseudogap at around the Fermi level. Onset energies of the spectra of the quasicrystals showed shifts to the higher energy side by 0.3 eV for Al75Cu15V10 and Al73Co27 and 0.8 eV for Al70Pd20Mn 10 compared to that of aluminum. Those results show that a decrease of valence charge at Al sites is characteristic for Al-based quasicrystalline materials. It may be attributed to an increase of covalency in bonding nature of the quasicrystalline materials.