Li enrichment of LiF surfaces bombarded by MeV nitrogen ion beams
Abstract
The PDMS (Plasma Desorption Mass Spectrometry) technique was employed for monitoring surface modifications in a LiF sample under ion bombardment at different doses. The flux of the 2.5-MeV N + beam was kept at 10 10 particles/s (∼ 1 n nA) to induce radiation effects in the LiF sample and was decreased to ∼ 500 particles/s during the PDMS analysis. The resulting time-of-flight spectra exhibit peaks characteristic of the sample, Li + and Li 2F +, and others such as H + and C 2H n+, originated by the ionization of the adsorbed layer. It was observed that only the desorption yields corresponding to the LiF species present a dose dependence. This result is interpreted in terms of Li enrichment of the surface due to F,H center defect production.
- Publication:
-
Nuclear Instruments and Methods in Physics Research B
- Pub Date:
- May 1997
- DOI:
- 10.1016/S0168-583X(96)00871-3
- Bibcode:
- 1997NIMPB.127..157P