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Ion surface interactions
  Molecular Physics seminar

Thursday 24 May 2012
from 10:15 to 11:00
at FA31
Speaker : Prof. Fritz Aumayr (TU Vienna, Austria)
Abstract : We have recently discovered that the impact of individual slow highly charged ions (HCI) is able to cause permanent nano-sized hillocks on the surface of a CaF2 single crystal [1]. The experimentally observed threshold of the projectiles’ potential energy necessary for hillock formation could be linked to a solid-liquid phase transition (nano-melting). Meanwhile, a variety of materials has been found to be susceptible to nano-structuring by slow HCI impact [2]. Nature, appearance, and stability of those structures, however, all depend markedly on the target material properties, and on its interactions with the HCI, which are governed by the potential and kinetic energy of the projectiles [2]. Thus, HCI impact does not always result in nano-hillock formation. In this talk we report systematic studies for HCI impact on thin films of PMMA and ultra-thin carbon nano-membranes, in which nano-craters and nano-pores milled into these samples due to individual HCI impact have been observed. [1] A. S. El-Said, et al., Phys. Rev. Lett. 100 (2008) 237601 [2] F. Aumayr et al., J.Phys.: Cond.Mat. 23 (2011) 393001

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