Alkali ion scattering from sputter-induced Au nanoclusters

ORAL

Abstract

The neutralization of scattered 3 keV $^{23}$Na$^{+}$ ions is used to probe the confined states of sputter induced Au nanoclusters on a TiO$_{2 }$(110) substrate. The neutral fraction of Na scattered from Au nanoclusters deposited on TiO$_{2}$(110) is high compared to bulk Au, as described earlier (G.F. Liu, Z. Sroubek, J.A. Yarmoff, Phys. Rev. Lett. \textbf{92}, 216801 (2004)). Here, normal incidence 0.5 keV Ar$^{+}$ ion bombardment of a thin Au film is employed as an alternative method for the self-organized formation of Au nanoclusters. The interplay between curvature dependent sputtering and surface diffusion during Ar$^{+}$ bombardment works to develop the Au nanoclusters. The neutral fraction of the scattered Na gradually increases from 5{\%} to 50{\%} as the cluster dimensions decrease due to the Ar$^{+}$ sputtering. XPS is used to quantify the reduction of Au coverage with sputtering time. STM revels a decrease of both the rms roughness and the correlation length of Au nanoclusters with Ar$^{+}$ fluence.

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Authors

  • P. Karmakar

  • G.F. Liu

    • Department of Physics, University of California, Riverside, California 92521

  • Z. Sroubek

    • Institute of Radio Engineering and Electronics, Czech Academy of Science, Chaberska 57, 182 51, Prague 8, Czech Republic

  • J.A. Yarmoff

    • Department of Physics, University of California, Riverside, California 92521