Phase formation induced by ion irradiation and electrical resistivity of aluminum-3d-transition-metal alloys

The phase formation, in particular amorphization, caused by 500 keV Xe exp + ion irradiation of thin multilayered films of Al--Ti, Al--V, Al--Cr, Al--Mn, Al--Fe, Al--Co, and Al--Ni has been investigated. At a substrate temperature of 100K during the irradiation, all these alloy systems are found to become amorphous for Al-rich compositions. At room temperature, the formation of structurally simple-crystalline solid solutions over extended compositional ranges, as compared to thermodynamic equilibrium, is observed. The electrical resistivity of amorphous Al sub 83 M sub 17 alloys, where M = Ti, vanadium, Cr, Mn, Fe, cobalt, or Ni, is found to vary systematically as a function of transition-metal element. A maximum is observed around Fe, for which the d-electron states coincide with the Fermi level. This behavior suggests that scattering of the conduction electrons by the 3d-electron states plays a dominant role. A comparison with X-ray photoelectron spectroscopy data from the literature suggests that the resistivity of amorphous Al sub 83 M sub 17 alloys can be directly correlated to the position and width of the d-electron states.