Auger electron and characteristic energy loss spectroscopy of some metals

Abstract

A sensitive high resolution three grid electron energy analyser has been constructed and has been used to measure the Auger electron and characteristic energy loss spectra of clean Cu, Au, Be, Al and Fe. In addition spectra of Cu black and Au black surfaces have been obtained. The experimental resolution of the instrument has proved to be -0.2% (which may be compared with a figure of about 2% for normal commercial analysers). All surfaces were prepared in ultra high vacuum (working pressure -10-10 torr) with the exception of Cu black and Au black, which were transferred to the UHV system from high vacuum after preparation. Changes in the electron spectra of Al, Be and Fe due to slow oxidation from residual oxygen were extensively studied. For these metals (Be, Al and Fe) fine structure in the Auger spectra involving the valence band has been interpreted in terms of the density of states of the valence band. Additional fine structure in the Auger spectrum of clean Al has been attributed to plasmon gain and loss mechanisms. In addition explanations of various other changes in the electron spectra of the metals, Be, Al and Fe, as a result of oxidation have been included.