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Title: Electronic structure of quasicrystalline surfaces: Effects of surface preparation and bulk structure

Electronic structure of quasicrystalline surfaces: Effects of surface preparation and bulk structure We elucidate the nature of the surface electronic properties of quasicrystalline Al-Pd-Mn. We do this by using photoelectron and Auger electron spectroscopies, and by making a variety of comparisons -- across types of bulk samples, and across methods of surface preparation. The main conclusions are these: (i) The narrow Mn 2p{sub 3/2} core-level line observed in the icosahedral phase is a fingerprint of a suppression in the density of states (a pseudogap) at the Fermi level and is not unique to the quasicrystalline phase. It is also independent of the symmetry of the quasicrystalline surface. The Auger line shape is also affected and may be used as a fingerprint of a pseudogap. (ii) A similarly narrow Fe 2p{sub 3/2} core-level line characterizes the icosahedral Al-Cu-Fe quasicrystal, consistent with the expectation that the electronic structure is of general importance in the stabilization of icosahedral phases. (iii) In icosahedral Al-Pd-Mn, the pseudogap of the bulk is not retained up to the surface immediately after fracture, but can be restored by annealing, or by sputter annealing to sufficiently high temperatures. Assuming that the pseudogap reflects an electronic stabilization of the atomic structure, these results suggest that the heat-treated surfaces are more stable than more » the surface obtained by fracturing at room temperature. « less
Authors: ; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:OSTI ID: 40205652
Resource Type:Journal Article
Resource Relation:Journal Name: Physical Review B; Journal Volume: 62; Journal Issue: 21; Other Information: Othernumber: PRBMDO000062000021014049000001; 003045PRB; PBD: 1 Dec 2000
Sponsoring Org:(US)
Country of Publication:United States
Language:English
Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANNEALING; ELECTRONIC STRUCTURE; ELECTRONS; FERMI LEVEL; FRACTURING; SHAPE; STABILIZATION; SYMMETRY