ELECTRONIC DISTRIBUTIONS OF AL-MN AND AL-MN-SI ALLOYS

Electronic distributions of various symmetries have been investigated for both valence and conduction bands in a series of Al-Mn and Al-Mn-Si alloys of different structural states (amorphous, quasi-crystalline or crystalline) and Mn concentrations ranging from 14 to 22at.%. Experiments have been carried out by means of soft-x-ray emission and photoabsorption spectroscopies. This allowed us to provide a complete description of the valence band states and to confirm the progressive opening of a small gap in the Al-Sp DOS at the Fermi level with increasing Mn concentration in the alloys. At a given Mn concentration the gap is wider for the quasi-crystalline phase than for its crystalline counterpart.