Validation and accuracy of peak synthesis software for XPS

VAMAS format data files have been generated and used to test the fitting capability of three commercial software systems A, B and C. The files simulate four synthetic materials, PMMA, PVA, PVC and PIB. They comprise GaussrLorentz peaks, 1 eV wide, on a small Shirley background. For each material the peaks are generated in either GaussrLorentz product or sum function forms. Software A synthesised peaks using the product functions and systems B and C the sum functions. Initial tests showed that C could not deal effectively with the Shirley backgrounds and so a special set of structures was generated for C without the Shirley backgrounds. All of the systems fitted well to resolved or partly resolved peaks of a type that corresponded with the form of peak used in the software but rather more poorly for those that did not correspond. It is shown therefore that, for experimental data, the energy and intensity errors will be larger than expected and will depend, significantly, on the software system used. Crown Copyright q1999 Published by Elsevier Science B.V. All rights reserved.