Nanopores fabricated in 1nm thick carbon nanomembranes by slow highly charged ions

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 projectile's potential energy necessary for hillock formation could be successfully linked to a solid-liquid phase transition (nano-melting) [1 - 3]. Meanwhile a variety of materials has been found, which are susceptible to nanostructuring by the impact of slow HCI [3]. The nature, appearance and stability of the created structures, however, depend heavily on the properties of the target material and the involved interaction processes (determined by the potential and kinetic energy of the projectiles) [3]. Not in all cases nano-hillocks are formed on the surface but also nano-craters or -holes have been found, e.g. on KBr [4] or PMMA [5].