Estudio de parámetros atómicos y moleculares en ... - FaMAF

Experimental K-shell ionization cross sections by electron impact were determined for C, O, Al, Si
and Ti. For this purpose, thin films were deposited on carbon and silicon substrates and their X-ray
emission spectra were analyzed, taking into account the influence of the substrate. The results obtained
were compared with the scarce experimental data available in the literature and with empirical and
theoretical models based on plane and distorted wave Born approximations (PWBA and DWBA,
respectively) and with the Bethe model with relativistic corrections.
The results achieved in this thesis were applied in the field of electron probe microanalysis in
order to improve a standardless quantification algorithm, based on parameters refinement (similar to
the well known Rietveld Method, used in X-ray diffraction).
The researches performed in the framework of this thesis will contribute to a deeper knowledge of
processes involved in electron and photon interaction with matter through the investigated atomic
parameters. The advances may be extended to other spectrometric techniques, or will be useful to face
non-conventional situations in electron microprobe analysis, such as standardless quantification of
single particles and rough samples or chemical bounding analyses by studying modifications in the X-
ray characteristic spectrum.
Key words: electron probe microanalysis, EDS, WDS, peak asymmetry, detection efficiency, Voigt
function, ionization cross section, X-ray emission spectra, satellite lines, standardless quantification.
iv