Site-specific neutralization of low energyLi+7scattered from Na/Al(100)

Site-specific neutralization is seen for low energy (1–5 keV) ${}_{}{}^7{}_{}{}^{}\mathrm{Li}_{}^{+}{}_{}{}^{}$ ions scattered at large angles from Na-covered Al(100). Energy spectra of the ion yield are collected near the surface normal as a function of Na coverage. ${\mathrm{Li}}^{+}$ singly scattered from Na is almost completely neutralized, while the neutralization of ions scattered from Al is fairly insensitive to coverage, indicating a large difference in the local electrostatic potential above Na and Al sites. This shows that the phenomena of resonant charge exchange is capable of resolving atomic scale variations in the surface potential.