The Study Of Surface Plasmons With Scanning Probe Electron Energy Spectroscopy

Nowadays scanning probe technique has been one of the most important analytical tools in surface science, which could detect the topography and the electronic structure near the Fermi level of the surface. However the principle of scanning probe technique prevents it from detecting the energy spectrum, which has restricted its application in elementary analysis from solid surface and spectrum imaging. The combination of scanning probe technique and electron energy spectroscopy measurement technology is a promising way to solve this problem. This thesis introduces the simulating and experimental results based on a scanning probe electron energy spectrometer (SPEES), including: the simulation of the tip field distribution and the flying features of emission electrons during the tip-sample region of the SPEES, the electron energy spectrum obtained by the scanning energy mode of the SPEES and the experimental results of surface plasmon's relative intensity distributions with the tip voltage and tip-sample separation.Chapter 1 describes some basic concepts in the identification of surface atoms, the progress of the spectrum imaging, the principle of the scanning tunneling microscope and recent progresses in SPEES, the principle of surface plasmon (SPs) and the advantages of the SPEES in the experimental research of the SPs.In chapter 2, we have presented a simulation study of the emission features of the Auger electrons in the electric field region localized within the cylindrical tip shield in SPEES. The influences of every detailed process have been taken into account synthetically and the relative current intensity distributions for outgoing Auger electrons have been calculated theoretically.Chapter 3 briefly introduces the structure of the SPEES. The experiment conditions and the preparation works are also explained.Chapter 4 describes the double detecting modes of SPEES: the fixed-point energy mode and the scanning energy mode. For the first time we obtained an energy spectrum of solid surface under the scanning mode of SPEES. The results confirm that the scanning mode could avoid error from the correction of response function.Chapter 5 introduces the SPs experimental results with four different thicknesses of Ag and Au samples in Highly ordered pyrolytic graphite (HOPG) substrate. The results indicate that the relative intensity of SPs intensifies with the tip voltage increasing and tip-sample separation decreasing. We attempt to interpret the principle from the multiple impacts of the scattering electrons and the relaxation time of the SPs oscillation.