An analog technique for the measurement of Auger electron currents: Application to sulfur on Ni(110)

Abstract

The conventional potential modulation technique employed in Auger electron spectroscopymeasures the derivative of the electron energy distribution (d N / d E). A technique is described for recovering the energy distribution itself and the area under an Auger feature via electronic integration of the measured signal. This integration is conveniently performed using operational amplifier technology. This technique is demonstrated in a retarding field analyzer in the particular case of sulphur in a c(2×2) structure on a Ni(110) surface. The measured area under the sulphur Auger peak follows the square law dependence on oscillator modulation amplitude predicted by Houston. A quantitative comparison is made between the sulphur Auger signal strength, as measured by the area under the Auger peak, and that predicted by the calibration performed by Perdereau for this system. The sulphur (L2,3VV) Auger peak shape in the N(E) spectrum, as obtained by integration, was found to be in good agreement with that observed by other workers.