Role of electronic excitations in the energy loss ofH2+projectiles in high-κmaterials

Abstract

In the present work we report on the energy loss ratio R n of fast H 2 + clusters in thin films ͑30-50 Å͒ of LaScO 3 and HfO 2 . The medium energy ion scattering technique was employed covering a broad energy range ͑40-200 keV/amu͒. The energy loss ratio data showed no clear evidence of collective excitations in these materials. The experimental results were interpreted in terms of three different theoretical approaches: the dielectric formalism with the Brandt-Reinheimer theory for semiconductor materials; the detailed simulation of the molecular fragments dynamics through the target; and finally the unitary convolution approximation adapted for hydrogen molecules. Only the simulation agrees with the experimental results for both oxides. The unitary convolution approximation works quite well for HfO 2 but overestimates slightly the LaScO 3 data. The overall results indicate that the energy loss ratio depends critically on the description of the electronic properties of such oxides.

Energy loss of swiftH2+andH3+Shubeita1, Grande2, Dias3 et al. 2011Phys. Rev. BSelf Cite132130View full textAdd to dashboardCite

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