Observation of ion tracks on GaN and TiO2 surfaces by AFM and GISAXS

Swift heavy ions have found widespread use in research and technology, for both materials analysis and modification. Having a kinetic energy in the MeV range and above, their usability now spans diverse fields such as hadron therapy, industrial production of track etched membranes and testing of electronic devices against single-event upsets. Impact of the swift heavy ion leads to intense heating of the material due to electron–phonon coupling and often triggers melting in a nanoscale volume along the ion trajectory. Upon rapid resolidification, permanent damage called an ion track is formed. At the surface, various nanostructures can be found on the position of the ion impact by means of atomic force microscopy. In recent years particular attention was given to grazing incidence swift heavy ion irradiation that yields ion tracks on the surface in the form of long chains of nanodots. In the present contribution we show that such ion tracks on the surfaces can be also investigated by grazing incidence small angle X-ray scattering. Examples of the observation of surface ion tracks on GaN and TiO2 surfaces are presented.