Energy loss spectra of H + and He + scattered off clean and K-covered Pd surfaces

Abstract

In the last years we studied the energy loss of low-energy (0.5–5 keV) particles incident under grazing incidence on metal surfaces for some simples systems, e.g. He and H on Ni and Pd surfaces [H. Derks et al., Nucl. Instr. and Meth. B44 (1989) 125, A. Närmann et al., Phys. Rev. Lett. 64 (1990) 1601, A. Närmann et al., Nucl. Instr. and Meth. B69 (1992) 158]. The detector is placed in specular direction. In this way we only probe the surface region. We want to investigate the effect on energy loss when using systems with different electronic structure. This was performed by depositing layers of potassium onto a metal surface and thereby varying the electron density at the surface. The question is, how can we explain the experimental results, which description of the surface properties does fit the experimental results best?