LOW-TEMPERATURE SELF-ION IRRADIATION OF PURE AND GRANULAR ALUMINUM-FILMS

Al-films, evaporated at room temperature under different oxygen partial pressures, were irradiated with self-ions (500 keV, Al++) at low temperature (<7 K). The observed increase of the resistivity and of the superconducting transition temperature Tc depends strongly on the oxygen content c0 present in the layers. A qualitative different behaviour of the above quantities was found for different fluence ranges of the bombarding ions. For high fluences in all cases an oxygen stabilized disorder state was obtained with corresponding Tc-increases between ΔTc=0.2 K for the purest films (c0≦0.5 at %) and ΔTc =1.2 K for films with 〈c0〉=40 at %. The annealing behaviour of the irradiated films is also dependent on the oxygen content c0. © 1979 Springer-Verlag.