RESUMO
We show, both experimentally and theoretically, a novel route to obtain giant room temperature spin-Hall effect due to surface-assisted skew scattering. In the experiment, we report the spin-Hall effect in Pt-doped Au films with different thicknesses t(N). The giant spin-Hall angle γ(S)=0.12±0.04 is obtained for t(N)=10 nm at room temperature, while it is much smaller for the t(N)=20 nm sample. Combined ab initio and quantum Monte Carlo calculations for the skew scattering due to a Pt impurity show γ(S)â 0.1 on the Au (111) surface, while it is small in bulk Au. The quantum Monte Carlo results show that the spin-orbit interaction of the Pt impurity on the Au (111) surface is enhanced, because the Pt 5d levels are lifted to the Fermi level due to the valence fluctuation. In addition, there are two spin-orbit interaction channels on the Au (111) surface, while only one in bulk Au.
RESUMO
Several kinds of materials were examined for the usefulness as releasing agents in the preparation of various thin self-supporting target films for use in nuclear reaction experiments. NaCl, BaCl2, KCl, CsI, Teepol, glucose, KIO3, mica, nitrocellulose or Formvar was deposited onto glass plates as the release agent by vacuum evaporation or dipping method. The obtained target film was tested on impurities from the release agent by using nuclear reactions. The relative effectiveness of each release agent was also considered from ease in the stripping of target films.