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

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• 作者：D. Primetzhofer
• 关键词：RBS ; MEIS ; Stopping power ; Protons ; HfO2 ; Electronic stopping
• 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• 出版年：1 February, 2014
• 年：2014
• 卷：320
• 期：Complete
• 页码：100-103
• 全文大小：654 K

文摘

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) 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.