Nanostructuring surfaces and 2D materials using swift heavy ions

Swift heavy ion irradiation emerged as a versatile tool to modify material properties on the nanoscale, due to very intense yet extremely localized excitation of the material. Even single ion impacts can induce drastic changes in the materials in the regime of the so called “swift heavy ions” (m > 20 amu, E > 1 MeV/amu). Nanoscale material transformation along a swift heavy ion 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 swift heavy ion beam is applied under grazing angles of incidence [1, 2, 3]. In the first part of our contribution, we present recent advances in surface modifications using swift heavy ions. Novel features of the ion impact sites morphology we found in GaN [4], SiC [5] and ITO thin film [6]. After high fluence ion irradiation, yet another new feature was found: straight, uniform, nanoscale ripples were observed in a narrow range of irradiation parameters for the first time [6]. A multitechnique approach is presented for the rutile TiO2 system [7], where atomic force microscopy, grazing incidence small angle X-ray scattering, and elastic recoil detection analysis provide complementary information. Finally, manipulation of these nanoscale surface modifications by means of etching and annealing are presented [6]. In the second part, the focus will be on the results of swift heavy ion irradiation of graphene. This wonder material shows a great deal of susceptibility to this kind of irradiation, and nanoscale modifications in the shape of ruptures and foldings were reported [3]. The threshold for this kind of nanostructuring was established [8], and we demonstrated that even small scale accelerators can be utilized for this purpose. The role of other system parameters (substrate, interfacial water layer) is discussed as well [9]. [1] E. Akcoltekin, T. Peters, R. Meyer, A. Duvenbeck, M. Klusmann, I. Monnet, H. Lebius, M. Schleberger, Nature Nanotech. 2 (2007) 290. [2] M. Karlusic, S. Akcoltekin, O. Osmani, I. Monnet, H. Lebius, M. Jaksic, M. Schleberger, New J. Phys. 12 (2010) 043009. [3] S. Akcoltekin, 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] M. Karlusic, R. Kozubek, H. Lebius, B. Ban d’Etat, R.A. Wilhelm, M. Buljan, Z. Siketic, F. Scholz, T. Meisch, M. Jaksic, S. Bernstorff, M. Schleberger, and B. Santic, J. Phys. D: Appl. Phys. 48 (2015) 325304. [5] O. Ochedowski, O. Osmani, M. Schade, B.K. Bussmann, B. Ban d’Etat, H. Lebius, M. Schleberger, Nature Comm. 5 (2014) 3193. [6] M. Karlusic et al., unpublished. [7] M. Karlusic, S. Bernstorff, Z. Siketic, B. Santic, I. Bogdanovic-Radovic, M. Jaksic, M. Schleberger, M. Buljan, J. Appl. Cryst. (submitted). [8] O. Ochedowski, O. Lehtinen, U. Kaiser, A. Turchanin, B. Ban-d’Etat, H. Lebius, M. Karlusic, M. Jaksic, M. Schleberger, Nanotechnology 26 (2015) 465302. [9] O. Ochedowski, B. Kleine Bussman, B. Ban-d’Etat, H. Lebius, M. Schleberger, Appl. Phys. Lett. 102 (2013) 153103.