The Ion-Matter Interaction with Swift Heavy Ions in the Light of Inelastic Thermal Spike Model |
| M. Toulemondea, C. Dufourb and E. Paumierb
aCIRIL, Laboratoire commun CEA-CNRS-ENSICAEN and Université de Caen, Bd H. Becquerel, BP 5133, 14070 Caen-Cedex 5, France bSIFCOM, Laboratoire commun CNRS, ENSICAEN and Université de Caen, 6 rue du Maréchal Juin, 14050 Caen-Cedex, France |
| Full Text PDF |
| Received: 2005 20 05; |
| A description of the inelastic thermal spike model is presented in order to correlate the energy deposited by swift heavy ions to the nanometric matter transformation induced in inorganic metallic and insulating materials. Knowing that insulator is more sensitive than metallic material and that amorphous material is in general more sensitive than a crystalline one, it appears evident that the electron-phonon coupling constant g plays a key role. It will be shown that in metallic material we are able to describe different phenomena with the same value of g: for example, track formation with defect annealing or sputtering of atoms. In insulators the emphasis is made on results obtained for amorphizable materials like SiO2 quartz and for non-amorphizable ionic crystals like CaF2. Assuming that tracks result from a transient thermal process, a quantitative development of the model is proposed using the electron-atom mean free pathλ (inversely proportional to the square root of g) as a free parameter. With this parameter it is possible to quantitatively describe track radii in a wide range of ion velocities - whatever the bonding character of the crystal is - assuming specific criteria: tracks may result from a rapid quenching of a cylinder of matter in which the energy deposited on the lattice has overcome either the energy necessary to reach a quasi-molten phase in the case of amorphizable materials or the vaporization energy in the case of non-amorphizable materials. The evolution of theλ parameter of the considered insulator decreases versus the band gap energy. In this model, velocity effect, and a link between track formation and sputtering of atoms is established for amorphizable insulators while open questions appear for ionic crystals. |
| DOI: 10.12693/APhysPolA.109.311 PACS numbers:61.80.Az, 61.80.Jh |