ION-INDUCED ATOMIC-LIKE LMM AND L2MM AUGER-ELECTRON EMISSION FROM MG,AL, SI, AND MGXAL1-X - ROLE OF SYMMETRICAL AND ASYMMETRIC COLLISIONS

We present a detailed study on Auger-electron emission from sputtered light-target atomic species (Mg, Al, and Si) with one and two initial 2p core vacancies by low-energy (2-15 keV) noble-gas-ion bombardment o n elemental and MgxAl1-x alloy samples. We show that the Al atomic LMM peak shape varies sensitively with primary energy for Ar+ but not for Ne+, Kr+, and Xe+ projectiles, that the high-energy spectral regions of all three elements consist of many previously unresolved atomic lin e structures, and that the L2MM-to-LMM intensity ratio depends on both primary ion energy and incidence. angle. Adiabatic molecular-orbital correlation diagrams are also computed for describing the 2p core-elec tron promotion. Our results clearly show the differences in contributi ons of symmetric and asymmetric collisions to single and double inner- shell-electron excitation in different systems.