Electronic stopping power of hydrogen in HfO2 at the stopping maximum and below

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:320

Article

Primetzhofer, D.

关键词: RBS;    MEIS;    Stopping power;    Protons;    HfO2;    Electronic stopping;   

DOI  :  10.1016/j.nimb.2013.11.004

来源: Elsevier

【 摘 要 】

Electronic energy loss of hydrogen ions in HfO2 was investigated in a wide energy range in the medium and low energy ion scattering regime. Experiments by Time-Of-Flight Medium-Energy Ion Scattering (TOF-MEIS) with proton and deuteron projectiles were performed in backscattering geometry for nm-films of HfO2 on Si with an ultrathin SiO2 interface layer prepared by ALD. At energies around the stopping maximum excellent agreement is found with earlier results from Behar et al. (2009) [45] and theoretical predictions. Towards lower energies discrepancies between experiment and calculations increase slightly. The low energy data exhibits excellent velocity proportionality and indicates the absence of clear effects due to distinct electronic states. Thus, no apparent velocity threshold can be extrapolated from the experiments within the uncertainty of present data. The magnitude of the energy loss is discussed in terms of a free-electron model and compared with the expected electron densities from plasmon frequencies. (C) 2013 Elsevier B.V. All rights reserved.

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