INVERSE-PHOTOEMISSION AND SOFT-X-RAY EMISSION-SPECTRA OF AL-NI-CO DECAGONAL SINGLE QUASICYRSTAL

Inverse photoemission spectra (IPES) of a decagonal single quasicyrsta l Al72Ni12Co16 have been measured for various incident electron energi es E-i together with its Al L-2,L-3 soft X-ray emission spectra (SXES) . Both IPES and SXES show low intensity near the photon energy corresp onding to the Fermi level, which is consistent with an opening of a ps eudo-gap across the Fermi level. The IPES shows no strong resonance en hancement, suggesting apparently small density of the transition metal d states above the Fermi level, However, constant final state spectra of the inverse photoemission reveal faint humps around E-i = 62 and 7 6 eV, which might indicate resonances due to the Co and Ni ad-derived states, respectively. A shoulder structure at the low photon energy si de of the main band in the Al L-2,L-3 SXES becomes prominant for the l ower incident electron energy and is tentatively ascribed to the Ni 3p emission band. (C) 1998 Elsevier Science B.V.