Extracting more chemical information from X-ray photoelectron spectroscopy by using monochromatic X rays

Abstract

Monochromatized X-ray sources have been available for use in commercial X-ray Photoelectron spectrometers for more than 20 years. Nevertheless most X-ray photoelectron spectroscopic (XPS) data are collected using achromatic radiation. The advantages of using monochromatized XPS combined with high resolution data collection for the study of core and valence band XPS are discussed, with a focus on the latter region. Examples discussed include studies of metals and oxides. The importance of eliminating X-ray satellite features in obtaining lead oxide valence band spectra is illustrated, and the resulting valence band spectra are shown to be able to distinguish between the oxides. While the valence band region can be well understood by using a cluster model for oxides, the importance of using a band structure model is illustrated for graphite and molybdenum spectra. Possible band structure effects are reported in oxide valence band spectra.