Chemical consequences of carbon and nitrogen implantation into LiH

Abstract

The chemical consequences of carbon and nitrogen implantation into LiH were studied. ¹¹C and ¹³N atoms were injected by nuclear recoil implantation following the processes ¹⁴N(p, α)¹¹C and ¹⁶O(p,α)¹³N in BN/LiH and AI₂O₃/LiH powder mixtures with 13 MeV protons. The chemical products of the shortlived radiostopes ¹¹C and ¹³N were studied by radiochromatography (GC, HPLC). Main products were ¹¹CH₄ (65%) and ¹³NH₃ (35%) together with ¹³NH₃ (or ¹³NH₂) radicals (65%). In a second attempt, 250 keV ¹²C⁺ and ¹⁴N⁺ions from an accelerator were implanted into LiH single crystalline plates at 6 K. The analysis was performed in situ by optical absorption spectroscopy in the visible and infrared spectral region. The formation of C-H and N-H bonds at low temperatures was confirmed. Carbon implants are more able than those of nitrogen to build up complete reaction products such as CH₄.