Au表面等离子体激元激发的扫描探针电子能谱

结合扫描隧道显微镜（STM）与电子能谱仪是实现表面微区元素分析的途径之一．我们将环形电子能量分析器和三维扫描探针系统相结合，建立了一台扫描探针电子能谱仪(SPEES)．通过测量针尖近场发射束流激发的Au表面能量损失谱，我们用研究了Au原子的等离子体激元激发现象．进一步通过改变针尖－样品距离，我们研究了Au等离子体激元峰与弹性散射峰的强度比随针尖－样品距离变化的关系．研究结果发现该强度比与针尖－样品距离的关系并不是单调变化，而是在一个特定位置存在极大．

Surface plasmon excitation of Au in scanning probe electron energy spectroscopy

It is a promising way for the scanning tunneling microscope (STM) to implement elementary analysis on sample surface by combined with the electron energy spectrometer. We have developed a scanning probe electron energy spectrometer (SPEES) by combining a toroidal electron energy analyzer (TEEA) with a three-dimensional scanning probe system. According to the energy-loss spectrum of Au film on mica substrate initiated by the near field emission current of the tip, we studied the plasmon resonant excitation of Au surface with our SPEES. The relative intensity (RI) of Au surface plasmon was calculated as ratio of the energy loss peak area and the elastic peak area. By changing the tip-sample distance, the variation of the Au surface plasmon RI on tip-sample distance was studied, which represented a non-monotonic curve and showed a maximum.