ATOMIC AND ELECTRONIC-STRUCTURE OF DECAGONAL AL-PD-MN ALLOYS AND APPROXIMANT PHASES

The electronic structure of the decagonal phase Al70Pd13Mn17 and relat ed crystalline phases has been calculated using the self-consistent ti ght-binding linear-muffin-tin-orbital technique. The electronic densit ies of states and the spectral functions have been calculated via the real-space recursion technique. The structural models are based on the decagon-pentagon-hexagon tiling. Chemical short-range order is optimi zed using the information about the local densities of states. The pen tagonal columnar clusters (identified by Hiraga et al.) exhibit struct ural stability and play the role of a characteristic structural unit o f all the discussed phases. Formation of a pseudogap in the Al-sp band is observed and its origin and role in the stabilization of the decag onal phase is discussed.