NONLINEAR EFFECTS IN THE KINETIC ELECTRON-EMISSION INDUCED BY SLOW IONS IN METALS

The contribution to the kinetic electron emission coming from the exci tation of conduction band electrons in binary collisions with slowly m oving ions is analyzed. The scattering suffered by conduction band ele ctrons, which are described within the free electron model, on the eff ective potential created by the projectile is studied, taking into acc ount the shift of the Fermi sphere due to the nonzero velocity of the ion. The effective potential is calculated self-consistently within th e density functional theory for a static impurity embedded in an elect ron gas. Using the excitation rate of conduction electrons obtained fr om this nonlinear approach, the energy distribution of emitted electro ns is calculated within a transport equation formalism. (C) 1998 Elsev ier Science B.V.