SOME PROBLEMS OF ELECTRON-SPECTROSCOPY (AES, EPES) USING A RETARDING-FIELD ANALYZER

The retarding field analyser (RFA) proved to be advantageous in electr on spectroscopy due to its high luminosity and by providing LEED simul taneously with AES and EPES. RFA is very efficient for determining the inelastic mean free path of electrons by EPES. Dolinski et al measure d the elastic peak by repelling the electron beam using a bias potenti al on the sample. In this paper a further development of this procedur e is described supplying the true percentage of elastically scattered electrons collected by RFA. The percentage has been determined by our RFA with optimized bias potential of the sample for primary energies b etween 100 and 2000 eV. It was deduced from the high energy side of th e elastic peak because the background affects the detected signal on t he low energy side. The experimental curve of elastic reflection coeff icient is presented for indium. The measured elastic peak is distorted by the analyser. The spectrometer response of an RFA was determined b y analysing the peak shape of deflected electrons after optimization o f the bias voltage of the sample. The peak shape shows asymmetry since the low energy side differs from the Gaussian like high energy side. The distortion produced by RFA is similar to that observed by Taylor. It is enhanced by the background adjacent to the elastic peak. A compu ter algorithm was elaborated for reconstruction of the elastic and Aug er peaks. Corrected curve is presented for indium Auger peak.