Fluorescence detection of extended X-ray absorption fine structure in thin films

The linearity of the fluorescence detection of the Extended X-ray Absorption Fine Structure (EXAFS) signal of moderately thin film samples depends on the experiment geometry and on the sample thickness because of the self-absorption effect. The correction for thick samples has been extensively studied but there has not been reported a method which could be useable continuously for intermediate thickness. We propose an approximative method that, taking into account the sample thickness, will provide the correction of the EXAFS signal amplitude. In the present work, the correction is applied to two different systems: FeSi2 thin films and Co/Cu superlattices. After correction, the determination of the crystallographic phase of FeSi2 thin films over different sustrates has been carried out.