Creation of nanodots on mica surfaces induced by highly charged xenon ions

Experiments on nanostructure formation on muscovite mica surfaces irradiated by highly charged Xe29+ ions with a beam energy of 0.58 MeV and Xe30+ ions with two beam energies (0.6 MeV and 4.8 MeV) have been carried out on the 320 kV ECR platform at the Institute of Modern Physics (IMP), Lanzhou. The created nano-sized structures have been imaged using tapping mode atomic force microscopy. Hillock-like structures are clearly visible at the surface of the mica irradiated by Xe29+ ions (at 0.58 MeV) below the charge state threshold reported in earlier experimental investigations with a height (∼1.6 nm) nearly equal to the one observed by Xe30+ ions (at 0.6 MeV). Moreover when mica is irradiated by Xe30+ ions (at 4.8 MeV), regular nanodots have been observed with a surprisingly larger height of 3.3 nm, nearly the double than the one created by the impact of Xe30+ ions with kinetic energy of 0.6 MeV. The possible mechanism of insulator surface modification is discussed.