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 on elemental and ${\mathrm{Mg}}_{\mathit{x}}$${\mathrm{Al}}_{1\mathrm{-}\mathit{x}}$ alloy samples. We show that the Al atomic LMM peak shape varies sensitively with primary energy for ${\mathrm{Ar}}^{+}$ but not for ${\mathrm{Ne}}^{+}$, ${\mathrm{Kr}}^{+}$, and ${\mathrm{Xe}}^{+}$ projectiles, that the high-energy spectral regions of all three elements consist of many previously unresolved atomic line structures, and that the ${\mathit{L}}^2$MM-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-electron promotion. Our results clearly show the differences in contributions of symmetric and asymmetric collisions to single and double inner-shell-electron excitation in different systems.

• Received 2 October 1992

DOI:https://doi.org/10.1103/PhysRevB.48.9987