Auger electron emission in the interaction of slow Na+ ions with Al surfaces

Kinetic electron emission from Al surfaces by slow ions

“…Evaluation of the intensity of this structure appears to be strongly dependent on the subtraction of the background spectrum. Nevertheless, we find 30 that the intensity of this structure and peak I have similar dependence on projectile energy, suggesting that they originate in the same excitation mechanisms. Furthermore, the ratio between the intensities of the two structure results is independent of the electron emission angle e , 30 allowing us to rule out Auger decay inside the bulk of excited Na atoms as a possible assignment for the broad feature, since in this case this ratio should increase as ͑cos e ͒ −1 .…”

“…Nevertheless, we find 30 that the intensity of this structure and peak I have similar dependence on projectile energy, suggesting that they originate in the same excitation mechanisms. Furthermore, the ratio between the intensities of the two structure results is independent of the electron emission angle e , 30 allowing us to rule out Auger decay inside the bulk of excited Na atoms as a possible assignment for the broad feature, since in this case this ratio should increase as ͑cos e ͒ −1 . A similar structure was observed also in the case of a Neon projectile, 12 tentatively attributed to an Auger deexcitation process involving an electron from the solid.…”

The role of atomic collisions in kinetic electron emission from Al surfaces by slow ions

“…Here we extend and compare those results to the case of electron emission from Al surfaces under the impact of 250-1000 eV Na + ions which, due to their low ionization potential, do not release enough potential energy to give rise to the so called 0168-583X/$ -see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2006.12.045 potential electron emission [2], and have been recently used for studies of KEE [5,17,18]. For the Na + -Al system [17,18], electron promotion occurs either in binary collisions between the projectile and a target atom (asymmetric collisions) and between a fast recoil and another target atom (symmetric collisions).…”

“…doi:10.1016/j.nimb.2006.12.045 potential electron emission [2], and have been recently used for studies of KEE [5,17,18]. For the Na + -Al system [17,18], electron promotion occurs either in binary collisions between the projectile and a target atom (asymmetric collisions) and between a fast recoil and another target atom (symmetric collisions). Asymmetric collisions involve either projectiles that have been neutralized in the interaction with the surface [2] and survived ions.…”