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Kawasuso, Atsuo; Fukaya, Yuki; Hayashi, Kazuhiko*; Hashimoto, Mie; Ichimiya, Ayahiko
Physica Status Solidi (C), 4(10), p.3924 - 3927, 2007/09
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)In this study, we performed the positron energy loss spectroscopy measurements from several surfaces using energy-filtered reflection high-energy positron diffraction. For Si(111)-7
7 surface, we observed at least five distinct loss peaks. The interval of energy loss peaks is approximately 10 eV, which corresponds to the surface plasmon loss energy of silicon. The positron energy loss spectra are well-approximated by the Poisson distribution. The average excitation number of surface plasmon is 2.6 under the total reflection condition. This number is similar to what expected for electrons at zero glancing angle. Thus, positrons lose their energy due to surface plasmon excitation much more sufficiently than electrons. We found that the specular spot is broadened in the total reflection region especially at the tail part due to plasmon excitation.
Kawasuso, Atsuo; Fukaya, Yuki; Hashimoto, Mie; Ichimiya, Ayahiko
no journal, ,
We have been investigating several surface systems using reflection high-energy positron diffraction (RHEPD) during a decade. The advantage of this method is the appearance of total reflection of positrons at the first surface layer. That is, RHEPD is more capable to study surface structures than electron and X-ray diffraction methods. There are many possible applications in the surface science. In the first half of this talk, we present our recent research on the phase transition In/Si(111) surface. A part from the surface study, there are still open questions concerning positron-surface interactions. Strong interaction between positron and surface implies that some elemental processes, which are different from the case of electron, occur. In the latter half of this talk, we focus on the results of our positron energy loss measurements.
