Swift heavy ions: a versatile tool for nanoscale modifications and analysis

Swift heavy ion (SHI) irradiation emerged as a versatile tool to modify material properties on the nanoscale, due to the very intense yet extremely localized excitation of the material. Even single ion impacts can induce drastic changes in materials in the SHI regime (m > 15 u, E > 0.1 MeV/u). Nanoscale material transformation along the SHI trajectory, that is straight and several micrometers long, is in essence derived from a 1D excitation source. This feature is in particular interesting for structuring 2D materials and surfaces, when a SHI beam is applied under grazing angles of incidence [1, 2, 3, 4]. In the first part of our contribution, we present recent advances in surface modifications using SHIs. Novel features of the ion impact sites morphology we found in GaN [5], ITO thin films [6], and rutile TiO2 [7]. Graphene as a special material shows also a great deal of susceptibility to SHI irradiation, and nanoscale modifications with the shapes of ruptures and foldings were reported [3]. The threshold for this kind of nanostructuring was recently established [8], and we demonstrated that even small scale accelerators can be utilized for this purpose. In the second part we present several advances in materials analysis using SHI beams. These include elastic recoil detection analysis of nanoscale multilayers, in situ Rutherford backscattering in channeling for defect analysis, and imaging of biological samples using MeV-SIMS. [1] E. Akcöltekin, T. Peters, R. Meyer, A. Duvenbeck, M. Klusmann, I. Monnet, H. Lebius, M. Schleberger, Nature Nanotech. 2 (2007) 290. [2] M. Karlušić, S. Akcöltekin, O. Osmani, I. Monnet, H. Lebius, M. Jakšić, M. Schleberger, New J. Phys. 12 (2010) 043009. [3] S. Akcöltekin, H. Bukowska, T. Peters, O. Osmani, I. Monnet, I. Alzaher, B. Ban d’Etat, H. Lebius, and M. Schleberger, Appl. Phys. Lett. 98 (2011) 103103. [4] O. Ochedowski, O. Osmani, M. Schade, B.K. Bussmann, B. Ban d’Etat, H. Lebius, M. Schleberger, Nature Comm. 5 (2014) 3193. [5] M. Karlušić, R. Kozubek, H. Lebius, B. Ban d’Etat, R.A. Wilhelm, M. Buljan, Z. Siketić, F. Scholz, T. Meisch, M. Jakšić, S. Bernstorff, M. Schleberger, and B. Šantić, J. Phys. D: Appl. Phys. 48 (2015) 325304. [6] M. Karlušić et al., unpublished. [7] M. Karlušić, S. Bernstorff, Z. Siketić, B. Šantić, I. Bogdanović-Radović, M. Jakšić, M. Schleberger, M. Buljan, J. Appl. Cryst. (submitted). [8] O. Ochedowski, O. Lehtinen, U. Kaiser, A. Turchanin, B. Ban-d’Etat, H. Lebius, M. Karlušić, M. Jakšić, M. Schleberger, Nanotechnology 26 (2015) 465302.