Electron emission microscopy in retrospect and prospect

Abstract

Photoelectron microscopy developed as part of the general advance in electron optics and conventional electron microscopy. The recent emphasis on energy analysis through photoelectron spectroscopy has led to several related developments in which the possibility of obtaining photoelectron spectra from very small object areas has emerged. Either chemical analysis, and especially molecular chemical analysis, becomes possible from areas less than a square micrometre, or magnified images may be obtained by using closely selected electron energies. Both of these possibilities are realized in the Oxford photoelectron spectromicroscope, which is described. Other means of producing electron images include the use of metastable or fast atoms. The use of a magnetic field, which is an essential part of the Oxford instrument, introduces the opportunity for a number of novel techniques, which are also described.