title: Energy deposition by heavy ions: additivity of kinetic and potential energy contributions in hillock formation on CaF2.
abstract: Modification of surface and bulk properties of solids by irradiation with ion beams is a widely used technique with many applications in material science. In this study, we show that nano-hillocks on CaF2 crystal surfaces can be formed by individual impact of medium energy (3 and 5 MeV) highly charged ions (Xe(22+) to Xe(30+)) as well as swift (kinetic energies between 12 and 58 MeV) heavy xenon ions. For very slow highly charged ions the appearance of hillocks is known to be linked to a threshold in potential energy (Ep) while for swift heavy ions a minimum electronic energy loss per unit length (Se) is necessary. With our results we bridge the gap between these two extreme cases and demonstrate, that with increasing energy deposition via Se the Ep-threshold for hillock production can be lowered substantially. Surprisingly, both mechanisms of energy deposition in the target surface seem to contribute in an additive way, which can be visualized in a phase diagram. We show that the inelastic thermal spike model, originally developed to describe such material modifications for swift heavy ions, can be extended to the case where both kinetic and potential energies are deposited into the surface.
authors.affiliation: 1] Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China [2] Inst. of Applied Physics, TU Wien - Vienna University of Technology, 1040 Vienna, Austria.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Wang
authors.affiliation: CIMAP-GANIL, CEA-CNRS-ENSICAEN-Univ. of CAEN, F-14070 Caen Cedex 5, France.
authors.forename: C
authors.initials: C
authors.lastname: Grygiel
authors.affiliation: CIMAP-GANIL, CEA-CNRS-ENSICAEN-Univ. of CAEN, F-14070 Caen Cedex 5, France.
authors.forename: C
authors.initials: C
authors.lastname: Dufour
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: J R
authors.initials: JR
authors.lastname: Sun
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Z G
authors.initials: ZG
authors.lastname: Wang
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Y T
authors.initials: YT
authors.lastname: Zhao
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: G Q
authors.initials: GQ
authors.lastname: Xiao
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: R
authors.initials: R
authors.lastname: Cheng
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: X M
authors.initials: XM
authors.lastname: Zhou
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: J R
authors.initials: JR
authors.lastname: Ren
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: S D
authors.initials: SD
authors.lastname: Liu
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Lei
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Y B
authors.initials: YB
authors.lastname: Sun
authors.affiliation: Inst. of Applied Physics, TU Wien - Vienna University of Technology, 1040 Vienna, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Ritter
authors.affiliation: Inst. of Applied Physics, TU Wien - Vienna University of Technology, 1040 Vienna, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Gruber
authors.affiliation: CIMAP-GANIL, CEA-CNRS-ENSICAEN-Univ. of CAEN, F-14070 Caen Cedex 5, France.
authors.forename: A
authors.initials: A
authors.lastname: Cassimi
authors.affiliation: CIMAP-GANIL, CEA-CNRS-ENSICAEN-Univ. of CAEN, F-14070 Caen Cedex 5, France.
authors.forename: I
authors.initials: I
authors.lastname: Monnet
authors.affiliation: CIMAP-GANIL, CEA-CNRS-ENSICAEN-Univ. of CAEN, F-14070 Caen Cedex 5, France.
authors.forename: S
authors.initials: S
authors.lastname: Bouffard
authors.affiliation: Inst. of Applied Physics, TU Wien - Vienna University of Technology, 1040 Vienna, Austria.
authors.forename: F
authors.initials: F
authors.lastname: Aumayr
authors.affiliation: CIMAP-GANIL, CEA-CNRS-ENSICAEN-Univ. of CAEN, F-14070 Caen Cedex 5, France.
authors.forename: M
authors.initials: M
authors.lastname: Toulemonde