Electronic distributions of states in crystalline and quasicrystalline Al-Cu-Fe and Al-Cu-Fe-Cr alloys

Valence and conduction state distributions in a series of Al-Cu-Fe and Al-Cu-Fe-Cr alloys of different structural states and nominal compositions have been investigated by means of soft X-ray emission and photoabsorption spectroscopies. A complete description of the valence band is obtained. The DOS at E_F is observed to be very low which is consistent with the high resistivity values found for the icosahedral quasicrystalline phase. The existence of a wide pseudo-gap at E_F is evidenced, which is higher in the quasicrystal than in be related crystalline counterparts.