High- and Low-Energy Photoemission Study of Strongly Correlated Au–Ga–Ce Quasicrystal Approximants: Localized 4f Nature and Disorder Effects.

We have investigated the electronic structures of Ce-based 1/1 quasicrystal approximants Au_59.2Ga_25.7Ce_15.1 and Au_60.3Ga_26.1Ce_13.6 by hard X-ray photoemission (HAXPES) and high-resolution photoemission spectroscopy. The localized Ce 4f electronic states are revealed for both Au–Ga–Ce approximants. Moreover, disorders in the compounds notably affect their electronic states, which has been detected by the core-level HAXPES. Valence-band photoemission spectra show the slight spectral difference depending on the composition ratio, which can be explained by a rigid-band-like shift. [ABSTRACT FROM AUTHOR]