Scanning force microscopy of surface damage created by fast C60 cluster ions in CaF2 and LaF3 single crystals

Single crystals of CaF2 and LaF3 were exposed to 30-MeV C60 clusters from the tandem accelerator in Orsay, extending earlier irradiation experiments with monoatomic swift heavy ions to larger energy loss values. The irradiated crystal surfaces were investigated by scanning force microscopy (SFM) in contact mode. Topographic images reveal nanometric hillock-like structures protruding from the surface at each cluster impact site. The hillock diameter and height are analyzed and compared to monoatomic projectiles.