電子線を用いた準結晶の電子状態研究 : 準結晶の特徴は何か EELS Study of Electronic Structures of Quasicrystals and Approximant Crystals
Al L-shell excitation spectra of Al-based quasicrystals of Al<SUB>75</SUB>Cu<SUB>15</SUB>V<SUB>10</SUB>, Al<SUB>73</SUB>Co<SUB>27</SUB> and Al<SUB>70</SUB>Pd<SUB>20</SUB>Mn<SUB>10</SUB> 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 Al<SUB>75</SUB>Cu<SUB>15</SUB>V<SUB>10</SUB> and Al<SUB>73</SUB>Co<SUB>27</SUB> and 0.8 eV for Al<SUB>70</SUB>Pd<SUB>20</SUB>Mn 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.
日本結晶学会誌 49(1), 51-54, 2007-02-27
The Crystallographic Society of Japan