Naumović, Dusanka 2004-07-15 The structure and electronic structure of different high-symmetry surfaces of either quasicrystalline or approximant Al–Pd–Mn were studied by means of photoemission-based techniques such as X-ray photoelectron diffraction (XPD) and ultraviolet photoelectron spectroscopy. We find that the twofold (2f), 3f and 5f surfaces of icosahedral Al–Pd–Mn exhibit all the symmetry elements of the icosahedral non-crystallographic group. These XPD experiments can be modeled by single-scattering cluster calculations. The bulk-terminated icosahedral or approximant surfaces are recovered after ion sputtering followed by annealing at T≈500–600 °C. A wealth of ordered surface phases (with different compositions) are found after sputtering and depending on the annealing temperature as, for example, a crystalline bcc multitwinned phase (for T<400 °C) or a stable decagonal quasicrystalline surface (for T>650 °C). The icosahedral surfaces are characterised by a lowering of the density of states close to the Fermi edge, compatible with the opening of a pseudogap, as expected for a quasicrystal. The crystalline overlayers are characterised by a sharp Fermi edge, while the approximant and decagonal quasicrystalline surfaces also have a lowered density of states. application/pdf https://folia.unifr.ch/global/documents/299764 https://folia.unifr.ch/documents/299764/files/1_naumovic_ses.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.progsurf.2004.05.004 info:eu-repo/semantics/openAccess License undefined Progress in Surface Science. - 2004, vol. 75, no. 3-8, p. 205-225 quasicrystal approximant decagonal icosahedral Al–Pd–Mn X-ray photoelectron diffraction (XPD) ultraviolet photoelectron spectroscopy (UPS) info:eu-repo/classification/udc/53 Structure and electronic structure of quasicrystal and approximant surfaces: a photoemission study http://purl.org/coar/resource_type/c_6501