PAC studies on xenon irradiated Ti and Ni films and Ni-Ti multilayers

The perturbed angular correlation (PAC) method was applied to investigate the effects of irradiating Ni and Ti films as well as Ni-Ti bilayers and multilayers with 900 keV Xe2+ ions. The ≅ 200 nm thick layers were deposited onto Si substrates by electron gun evaporation in an UHV chamber. Some 1012 radioactive 111In ions were implanted at 400 keV. The PAC spectra of the Ni- and Ti-films measured at room temperature exhibit the known magnetic and electric hyperfine frequencies ωL = 95.7 MHz (Ni) and νQ = 27.3 MHz (Ti) typical for substitutional implantation. Xe-irradiations up to 2x1016 cm-2 did not change these parameters, but slightly increased the distribution widths. When irradiating Ni-Ti multilayers, amorphization was observed at a Xe-fluence of about 1015 cm-2. In addition, the RT mixing rate in Ti-Ni bilayers was measured via Rutherford backscattering. (orig.)