Scattering of Fast Ions and Energy Loss on Surfaces

Abstract

The interaction of fast ions with a solid surface is studied by the specular reflection of MeV H+ and He+ ions from clean surfaces of SnTe and PbSe single crystals. Oscillatory structure is observed in the energy spectra of reflected He+. This indicates that a part of the incident ions penetrate inside the crystal and travel for a few wavelengths of oscillatory motion in the (001) planar channel before reappearing at the surface. The position-dependent stopping power near the surface is derived from the observed energy loss of specularly-reflected ions. A large difference is observed in the charge-state distribution between the specular reflection and the transmission through a self-supporting foil. This is attributed to the fact that the specularly-reflected ions interact exclusively with the valence electrons. The technique of specular reflection of fast ions is applied to investigate the epitaxial growth of PbSe on a SnTe (001) surface. It is shown that the specular reflection is very sensitive to the surface distortion which is introduced in the first stage of the epitaxial growth.KeywordsMisfit DislocationSpecular ReflectionOscillatory StructureSurface DistortionStep DensityThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.