CONICET | Buscador de Institutos y Recursos Humanos

3D-micro X-ray fluorescence spectroscopy enables non-destructive three-dimensionalinvestigation of elemental distribution in samples in the micrometer regime. In the last few years, accurate quantification procedures have been developed. The most important problem in these quantification procedures is the existence of light elements in the sample from which no fluorescence is detected. This dark matrix problem is not yet solved and is now the most serious limitation of this technique. Resonant Raman scattering is an inelastic scattering process that becomes dominant when atoms are irradiated with incident energy lower and close to an absorption edge. Recently, a spectroscopic technique in formation based in this process showed to be useful to distinguish surrounded chemical environments. We present first results regarding the possibility of determining the oxidation state of an element, in a three-dimensional regime, by resonant Raman scattering using an energy dispersive system combined with a confocal setup. A depth scanning of a multilayer sample in confocal setup was carried out in the XRF Beamline of the LNLS (Campinas, Brazil). The sample consisted of different layers of Cu oxides over a Cu substrate. The sample was irradiated with monochromatic photons having energy close but lower than the K absorption edge of Cu. The Raman peaks were analyzed, residuals were determined and a FFT smoothing procedure, taking into account the instrument functions of the detecting system, was applied. The results show an oscillation pattern that depends on the oxidation state of cooper. The result is relevant since allows the discrimination of the oxidation state of the elements present in a sample in a 3D-micrometer regime by means of resonant Raman scattering combined with a confocal setup. This result could be used as a tool to determine the dark matrix present in the sample with the aim of establishing a reliable quantification procedure.