Abstract
Light emitted during the bombardment of beryllium and beryllium-oxide surfaces by 5 keV Kr+ ions is analyzed over the wavelength range 190-590 nm. A much larger photon yield is found when the target is an oxide. First, atomic lines are stronger. The analysis of their Doppler profile reveals the importance of collision sequences (Kr-O)-(O-Be) for the ejection of excited Be atoms. Secondly, a BeO target gives rise to luminescence. This is intense for medium angles of incidence and surprisingly declines steeply between 50 degrees and 60 degrees. Possible origins to luminescence are self-trapped excitons and F-centers. The intense emission from the BeO target contrasts with its absence for pure Be, which excludes radiation from surface plasmons. Bombardment of a BeO target also produces well-structured molecular bands. (c) 2006 Elsevier B.V. All rights reserved.