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A. El-Said, R. Wilhelm, R. Heller, S. Facsko:
"Creation of surface nanostructures in lanthanum fluoride single crystals by irradiation with slow highly charged ions";
Nuclear Instruments & Methods in Physics Research Section B, 460 (2019), 137 - 140.

Slow highly charged ions (HCI) were utilized successfully for the formation of various nanostructures in the
surfaces of different materials. The creation mechanism of HCI-induced nanostructures was intensively studied
in alkali- and alkaline-earth fluorides. Here, we are investigating another type of fluorine-containing ionic
crystals of different crystalline and electronic structure, namely lanthanum fluoride, LaF3. The single crystals
were irradiated with slow (eV-keV) highly charged xenon ions from an Electron Beam Ion Trap. After irradiation,
the crystals surfaces were investigated by scanning force microscopy. The measured topographic images show
nanohillocks emerging from the surface. These nanostructures were observed only after exceeding a well-defined
threshold in the potential energy. The role of ion parameters for nanohillocks formation as well as a comparison
with results for swift heavy ion irradiations of LaF3 single crystals are presented. Furthermore, the similarities
and differences between LaF3 and other ionic fluoride crystals, in the creation of surface nanostructures, are
discussed.

LaF3 Nanostructures Highly charged ions