A Multichannel Monitor for Repetitive Auger Electron Spectroscopy with Application to Surface Composition Changes

Abstract

A multichannel monitor has been designed to shorten the effective scanning time of Auger electron spectroscopy. The circuitry of the multichannel monitor is described with specific reference to its application to the second derivative curve of a retarding potential analyzer. By adopting the monitor to a retarding potential analyzer of a LEED system, sufficiently fast response time has been obtained to permit various kinds of surface kinetics to be monitored. By way of illustrating the use of the monitor, results are given of surface composition changes on the Ni(110) surface that accompany heating subsequent to adsorption at room temperature. It was found, for example, that surfacecarbon may cover surface sulfur and, consequently, on heating the latter suddenly appears as a result of the removal of carbon. In this manner the nature of surface sites occupied by various surface species can be characterized. And by monitoring the kinetics specific activation energies may be determined.