CONICET | Buscador de Institutos y Recursos Humanos

Recently, the capabilities of the micro-x-ray fluorescence spectroscopy (m-XRF) were expanded by the confocal setup. It consists of x-ray lenses in the excitation as well as in the detection channel. For intermediate thin homogeneous layers a scanning in the normal direction to the surface provides information of its thickness and elemental composition [1]. For multilayers samples it also provides the order of each layer in the stratified structure [2]. In the present work we propose a new quantification algorithm to apply in the surface analysis by confocal m-XRF. It is an iterative procedure valid to thin intermediate layers where the exponential attenuation of the x-ray fluorescent radiation cannot be approximated. The algorithm is a consequence of the application of the convolution theorem to the theoretical expression of the x-ray fluorescence emission produced in confocal m-XRF. The analytical expressions involved in the present quantification algorithm are the same as those used for quantification of intermediate thin layers by conventional XRF [3]. In this way, some of the analytical processes applied in conventional XRF can be adapted to confocal m-XRF. The new algorithm was applied to analyse by confocal m-XRF a sample of paint layers on a glass substrate. To test the precision of the proposed algorithm, the present results were compared with conventional XRF analysis.