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Abstract: Al2O3 single crystals were irradiated with slow highly charged Xe ions of various charge states from an EBIT (Electron Beam Ion Trap) source at the Dresden two source facility. The irradiations were performed at room temperature and under normal incidence. Scanning force microscopy (SFM) was utilized to investigate the topography of the irradiated surfaces. The measurements showed that above a potential energy threshold, each ion creates a nanohillock protruding from the surface. These structures are compared to those created by swift heavy ions (SHI). The results are discussed in terms of potential energy deposition of highly charged ions (HCI) and electronic energy loss of SHI. [Copyright &y& Elsevier]

Abstract: Lithium niobate (LiNbO3) single crystals were irradiated with high energy gold ions (0.5–2.2GeV) at the UNILAC (GSI) and with 150-keV highly charged xenon ions from an EBIT (Electron Beam Ion Trap, HZDR). The surfaces of the irradiated crystals were analyzed by scanning force microscopy showing very similar topographic changes. Swift heavy ions and slow highly charged ions produce hillock-like nanostructures on the surface. In both cases, the energy deposition of the ions is characterized by dense localized electronic excitations and efficient transfer to the lattice. Furthermore, the irradiation results in a shift in the band gap energy as evidenced by UV–Vis absorption spectroscopy. Specific modifications (e.g. hillock size, energy loss threshold) induced by slow highly charged ions are discussed in comparison with effects due to the electronic energy loss by swift heavy ions. [Copyright &y& Elsevier]

Abstract: Swift heavy ions (SHI) of MeV–GeV energy lead to the creation of nanometric surface structures as well as modifications in the bulk along the ion penetration depth. Recently, similar surface modifications have been observed for the impact of individual slow highly charged ions (HCI). Non-amorphizable ionic-halide single crystals, like KBr, CaF2 and BaF2, are considered as the most intensively studied materials after irradiation with HCI. In this contribution we study the creation of surface nanostructures in an amorphizable material, namely SiO2 quartz after irradiation with slow highly charged Xe ions from the Electron Beam Ion Trap at Helmholtz Zentrum Dresden-Rossendorf and swift xenon ions from Universal Linear Accelerator at GSI in Darmstadt. After irradiation at room temperature, the crystals were investigated by scanning force microscopy. For both SHI and HCI, the created nanostructures exhibit the shape of hillocks. Moreover UV–VIS spectroscopy was performed to identify the defects created by ion irradiation at high fluence. The results are discussed in terms of the creation mechanisms driven by the dependence on both potential and kinetic energies of the ions. [Copyright &y& Elsevier]

Abstract: The creation of surface nanostructures in BaF2 (111) surfaces was studied after irradiation with slow highly charged Xe ions from the Dresden-EBIT (electron beam ion trap). After irradiation, the crystals were investigated by scanning force microscopy (SFM). Using specific ion parameters, the topographic images show nanohillocks emerging from the surface. Additionally, we used the technique of selective chemical etching to reveal the lattice damage created by ion energy deposition below and above threshold needed for surface hillocks formation. The role of both potential and kinetic energy as well as a comparison with results for swift heavy ion irradiations of BaF2 single crystals are presented. [Copyright &y& Elsevier]

Alloys of composition Sn-8.5Sb-5.5Cu (in atomic percent) were rapidly solidified by a melt-spinning technique. The samples were irradiated at room temperature with GeV uranium ions of fluences between 9×108 and 9×1011 ions cm-2. X-ray diffraction analysis revealed the formation of a new-phase Cu11Sb3 as well as a reduction in the axial ratio (c/a) of the matrix (β -Sn) indicating the regular re-arrangement of atoms. Scanning force microscopy showed no surface topographic changes with the ion fluence. The mechanical properties (Young's modulus and hardness) of the irradiated alloys were studied as a function of ion fluence. The radiation-annealing process is discussed in terms of the evolution of both resistivity and hardness as a function of ion fluence. [ABSTRACT FROM AUTHOR]

Abstract: Yttrium iron garnet (Y3Fe5O12 or YIG), an amorphizable ferrimagnetic insulator, is probably the best studied material with respect to track formation and damage morphology. This paper presents first scanning force microscopy (SFM) of surface damage induced by energetic C60 clusters. YIG single crystals were irradiated at normal incidence with 30-MeV C60 cluster ions (kinetic energy ∼0.04MeV/u) provided by the tandem accelerator of the Institute of Nuclear Physics in Orsay (IPNO). The SFM topographic images show nano-protrusions on the YIG surface; where each hillock is generated by one C60 cluster. The role of stopping power and deposited energy density is discussed in terms of dimensional analysis of the nanostructures. Hillocks created by C60 clusters are compared with those produced by monatomic ions. [Copyright &y& Elsevier]

Abstract: We investigate the formation of nano-sized hillocks on the (111) surface of CaF2 single crystals by impact of slow highly charged ions. Atomic force microscopy reveals a surprisingly sharp and well-defined threshold of potential energy carried into the collision of about 14keV for hillock formation. Estimates of the energy density deposited suggest that the threshold is linked to a solid–liquid phase transition (“melting”) on the nanoscale. With increasing potential energy, both the basal diameter and the height of the hillocks increase. The present results reveal a remarkable similarity between the present predominantly potential energy driven process and track formation by the thermal spike of swift (∼GeV) heavy ions. [Copyright &y& Elsevier]