利用扫描隧道谱(STS)对石墨单晶表面局域电子态的研究

利用ＳＴＳ测量并结合扫描隧道显微镜（ＳＴＭ）扫描图象，给出一组沿石墨单晶表面原子分辨的ＳＴＭ图象上某一线段各点处的扫描隧道谱．ｄ（lｎI）／ｄ（lｎＶ）～ｅＶ由测量谱给出的样品表面Ｅ_Ｆ附近局域态密度分布与由体能带结构计算得到的结果在一定程度上相符合，将各条曲线中Ｅ_Ｆ附近的态密度峰能量对相应的空间位置作图，给出石墨表面E_F附近能态密度在测量区域内实空间的变化。通过对表面不等价Ａ，Ｂ类原子处局域电子结构的分析并利用简单模型进行计算，给出了与实验关键词：

A STUDY ON THE LOCAL ELECTRONIC STRUCTURE OF GRAPHITE SURFACE WITH SCANNING TUNNELING SPECTROSCOPY (STS)

By using STS, combined with STM imaging, the STS spectra d(lnI)/d(lnV) -eV were measured point by point along a line on the surface of a single crystal graphite. The local density of states (LDOS) around the Fermi level E_F obtained from the spectra showed basically an agreement with that of theoretical calculation. By plotting the energy positions of the LDOS peaks around E_F with respect to the measurement positions, the spatial variations of the energy band of graphite close to E_F were shown. With a discussion of the local electronic structure around the ine-quivalent A, B type atoms on the surface, a simple model calculation for the spatial variations of the energy band was conducted and that showed an agreement with the experimental results. By comparison of the results, the site of A type atoms on the graphite surface, which did not appear in the STM image, was determined.