Surface Properties of New Complex Metallic Alloys

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Complex Metallic Alloys (CMA) comprise a broad family of compounds, characterised by their large unit cells and their composition with clusters of atoms in the unit cell. The result of this is the physical properties of CMA are unique with respect to conventional metal alloys. Of particular interest are quasicrystals (QC), whose large unit cells and aperiodic crystalline structures have been found to have a unique combination of properties, with tribological applications as well as low conductivity and potential low cost. Although they have no translational symmetry, QC exhibit rotational symmetry forbidden in periodic crystals, such as 5, 10 and 12-fold rotational symmetry that require a higher number of basis vectors than spatial dimensions to describe the QC in reciprocal space.This research project has two areas of interest: (i) we will generate new QC nanostructures through atomic and molecular adsorption on quasiperiodic substrates and explore their structural and electronic properties. We propose to deposit molecules such as C60 or Pentacene using 3-fold surfaces of icosahedral quasicrystals as substrates, forming metallic thin film layers. These layers will be characterised with scanning tunnel microscopy (STM), low energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS). (ii) We will generate quasiperiodic tilings of sub-micron scale using nanolithography, and in particular investigate their structure and magnetic properties with scanning electron microscopy (SEM), magnetic force microscopy (MFM) and atomic force microscopy (AFM). The overall objective of this research is to understand electronic and magnetic properties of QC for technological applications.