[Back]

D. Kovacs, T. Peters, C. Haake, M. Schleberger, A. Wucher, A. Golczewski, F. Aumayr, D. Diesing:
"Potential electron emission induced by multiply charged ions in thin film tunnel junctions";
Physical Review B, 77 (2008), 2454321 - 24543211.

Thin film metal-insulator-metal tunnel junctions are used to investigate the electronic excitation process
induced by the impact of multiply charged ions onto a metallic surface. Hot charge carriers electrons and
holes generated by the dissipation of the kinetic and potential energies of the projectiles are detected as an ion
induced internal emission current from the bombarded "top" metal film into the "bottom" substrate electrode.
Results are presented for Arq+ ions with a kinetic impact energy of 1 keV and charge states q=1-8 impinging
onto an Ag-AlOx-Al junction. It is shown that the internal emission yield exhibits an approximately linear
dependence on the potential energy of the projectile. At low potential energy, a bias voltage applied between
the two metal films is found to strongly influence the internal emission current, whereas this influence becomes
much weaker with increasing projectile charge state. The results are shown to be qualitatively well described
in the framework of a thermodynamical free-electron model.
DOI: 10.1103/PhysRevB.77.245432
PACS number s : 79.20.Rf, 41.75.Ak, 73.40.Rw