Inverse photoemission and soft X-ray emission spectra of Al [sbnd]Ni [sbnd]Co decagonal single quasicyrstal

Abstract

Inverse photoemission spectra (IPES) of a decagonal single quasicyrstal Al 72Ni 12Co 16 have been measured for various incident electron energies E i together with its Al L 2,3 soft X-ray emission spectra (SXES). Both IPES and SXES show low intensity near the photon energy corresponding to the Fermi level, which is consistent with an opening of a pseudo-gap across the Fermi level. The IPES shows no strong resonance enhancement, 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 76 eV, which might indicate resonances due to the Co and Ni3 d-derived states, respectively. A shoulder structure at the low photon energy side of the main band in the Al L 2,3 SXES becomes prominant for the lower incident electron energy and is tentatively ascribed to the Ni3 p emission band.