Non-destructive determination of depth profiles with the aid of X-ray fluorescence analysis

Depth profiles of Ni/Fe-foils (5...20 μm thick) are determined by means of X-ray fluorescence analysis (XRF). The main prerequisite for applying this technique consists in a precise description of X-ray production. In media with depth dependent composition the enhancement effect plays an important role. If the foil thickness is of the order of the relaxation length of fluorescence radiation the measurements should be carried out both in reflection and in transmission and from both sides of the foil to get maximum information on the unknown concentration profile. The thickness of the foil may be gaged independently and simply by an absorption technique. For this reason only ratios (and not absolute values) of the X-ray yields should be determined in the experiment. In addition to this practical simplification, the averaged composition of the foil is obtained which is suitable for controlling XRF-profiling results. (author)