How well does total electron yield measure x-ray absorption in nanoparticles?

The possibility to quantitatively analyze total electron yield (TEY) spectra as a measure of the x-ray absorption cross section from supported magnetic nanoparticles is explored by a combination of experiments and Monte Carlo simulations. Unless the particles are very small, it is found that saturation effects are important and can lead to a severe underestimation of the magnetic moments, when the magneto-optical sum rules are straightforwardly applied to experimental data. However, unlike for planar samples the possibility to examine and correct the saturation effects by varying the x-ray angle of incidence is not given, the absorption profiles are largely unaffected in their shape. The Monte Carlo simulations, appropriately conducted for the material under investigation, provide an estimate of the saturation effects occurring in nanoparticle TEY data. (C) 2004 American Institute of Physics.