Berlin 2015 – scientific programme

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DS: Fachverband Dünne Schichten

DS 36: Poster Session I

DS 36.67: Poster

Thursday, March 19, 2015, 09:30–12:00, Poster A

Noble gas ion-induced ripple pattern formation on carbon surfaces — •Omar Bobes, Kun Zhang, and Hans Hofsäss — Georg-August-Universität Göttingen, II. Physikalisches Institut, Göttingen, Germany

Ion induced ripple pattern formation on HOPG, diamond and amorphous carbon surfaces were studied previously and a qualitative agreement with the predictions of the Bradly-Harper model, but also differences between HOPG and a-C were found [1,2,3]. Here we present new experiments for Ne, Ar and Xe ion irradiation of a-C surfaces as function of ion incidence angle and for ion energies between few hundred eV and 100 keV. We find a disappearance of patterns for Ne and Ar ion irradiation at ion energies higher than several keV. Monte Carlo simulations of the curvature coefficients applied to the Bradley-Harper and Carter-Vishnyakov models, including the recent extensions, are able to explain the absence of pattern formation in these cases. Moreover, simulations indicate that pattern formation on a-C should be possible for low energy Ne ions and even He ions with 250 eV. Indeed we find ripple patterns for 850 eV Ne irradiated a-C.

[1] S. Habenicht, Phys. Rev. B 63,125419 (2001).

[2] K. Takahiro et al., Nucl. Instr. Meth. B 256, 378 (2007).

[3] O. Bobes, K. Zhang, H. Hofsäss, Phys. Rev. B 86, 235414 (2012).