磁透镜引起的氯化银谱峰异常位移及其在X射线光电子能谱成象分析中的应用

Abnormal X-ray Photoelectron Spectroscopic Peak Shifts of AgCl Introduced by the XL Magnetic Lens and Its Application in Imaging X-ray Photoelectron Spectroscopic Analysis

用X射线光电子能谱 (XPS)分析了与样品托有良好电接触的银片及其上面的AgCl。观察到在使用样品磁透镜和非单色化X射线源的实验条件下不导电的AgCl的电子峰产生异常大的谱峰位移 ,还发现这种异常谱峰位移可以应用于XPS成象分析 ,以提高化学位移很小的元素化学态 (如Ag0 和Ag+ )的XPS象的分辨能力。

A flat AgCl/Ag specimen was analyzed using X-ray photoelectron spectroscopy (XPS). The Ag sheet in the specimen was electrically contacted with the stainless steel sample holder. The specimen was irradiated with unmonochromatized AlKα X-ray. The photoelectrons were collected using the XL magnetic lens. An abnormal peak shift up to 28.3 eV has been observed for Ag3d spectrum of insulating AgCl while no peak shift is observed for Ag3d spectrum of metallic Ag. This abnormal peak shift has been attributed to the charging effect introduced by the use of the XL magnetic lens. The chemical shift of Ag3d binding energy between Ag 0 and Ag + in AgCl is only 0.4eV, impling that AgCl can not be distinguished from metallic Ag in the Ag3d XPS image when the XL magnetic lens is not used. However, since Ag3d peak of AgCl shifts far from the Ag3d peak of metallic Ag when the XL magnetic lens is used, AgCl can be distinguished from metallic Ag in the Ag3d XPS image of AgCl/Ag specimen.