![]() ![]() These are mostly the 3d, 4d, and 5d transition metals, the lanthanides, and the actinides. The latter comprises all compounds containing elements with open valence shell electrons. The former generally will yield better accuracy, more easily, than the latter. The XPS of materials tends to fall into two broad classes: where the signals being used for quantification are “main” peaks, which are narrower and more symmetric, followed by a relatively low background with only weak satellite structure and where the “main” peaks are broader and often asymmetric, followed by backgrounds that are higher and have a stronger satellite structure. Issues involved are (1) the uncertainty of background subtraction of inelastically scattered electrons, (2) the accuracy of the RSFs, and (3) the role of XPS peak satellite structure, which affects both (1) and (2) above. We address accuracy (not precision, which is much more straightforward) using relative sensitivity factors, RSFs, obtained either empirically from standards (e-RSF) or from the use of theoretical cross sections, σ, (t-RSF). We consider only the use of conventional laboratory-based instruments with x-ray sources, Alk α or Mgk α. Nonhomogenous effects, such as composition variation with depth or severe topography effects (e.g., in nanoparticles), are not discussed. ![]() We present a perspective on the use of XPS relative peak intensities for determining composition in homogeneous bulk materials. ![]()
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