Fermi states and anisotropy of Brillouin zone scattering in the decagonal Al-Ni-Co quasicrystal.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 26443439.
- Also identified by DOI 10.1038/ncomms9607 and PMC identifier 4633949.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Quasicrystals (QCs) are intermetallic alloys that have excellent long-range order but lack translational symmetry in at least one dimension. The valence band electronic structure near the Fermi energy EF in such materials is of special interest since it has a direct relation to their unusual physical properties. However, the Fermi surface (FS) topology as well as the mechanism of QC structure stabilization are still under debate. Here we report the first observation of the three-dimensional FS and valence band dispersions near EF in decagonal Al70Ni20Co10 (d-AlNiCo) QCs using soft X-ray angle-resolved photoemission spectroscopy. We show that the FS, formed by dispersive Al sp-states, has a multicomponent character due to a large contribution from high-order bands. Moreover, we discover that the magnitude of the gap at the FS related to the interaction with Brillouin zone boundary (Hume-Rothery gap) critically differs for the periodic and quasiperiodic directions.