Electronic structure of icosahedral AlPdMn alloys

Abstract

Calculations are presented of the electronic structure of a hierarchy of rational approximants to icosahedral AlPdMn quasicrystals. A model for the atomic structure has been constructed via the projection method, using atomic surfaces appropriate to reproduce the diffraction patterns of the icosahedral phase. The electronic structure has been calculated self-consistently in the local-density approximation using the linear-muffin-tin-orbital (LMTO) method and tight-binding LMTO techniques. It is shown that the electronic density of states of the higher-order approximants is characterized by a structure-induced pseudogap at the Fermi-level. However, unlike the case for most quasicrystals investigated so far, no corresponding pseudogap exists for the lowest-order approximants.