Abstract
In this study, some of the fundamental aspects of neutralization of low-energy (10–300-eV) ions have been addressed in comparison with that of ions. To examine the role of the valence-band structure in determining neutralization rates for , a range of target materials has been studied (Mo, Ta, Ag, Pb, , CsCl, LiCl, AgCl, , etc.). The surface peak of is extremely small compared with that of in scattering from metal surfaces, while the contrary is sometimes true in scattering from ionic compounds such as alkali-metal halides and alkaline-earth halides. It is found that the neutralization of depends on the local electronic states of the target atom and occurs via the resonant neutralization by s- or d-band electrons of the metal atoms or via an energy-level-crossing mechanism between D 1s and the closed p band of the anions. The reason why the neutralization probability for is very much enhanced compared with that for is that the surface electronic state relevant to the resonant neutralization of is not a level but a broad valence band (band effect). It is concluded that the smaller ionization energy of deuterium than helium results in strong coupling of the D 1s level with the valence band.
- Received 14 May 1990
DOI:https://doi.org/10.1103/PhysRevB.42.7761
©1990 American Physical Society