Confocal X-ray Resonant Raman in combination with multivariate methods for 3D-reconstruction of chemical state distributions in stratified samples

LEANI J.; PÉREZ R.D.; ROBLEDO, J.; SÁNCHEZ H.J.

Brescia

Conferencia; 17th International Conference on Total Reflection X-Ray Fluorescence Analysis and Related Methods; 2017

X-ray resonant Raman scattering is used in a confocal setup with the aim of determining different compounds of the same element in a stratified sample. This allows us to resolve chemical environments with 3D-resolution using a detection system with low energy resolution. A depth scanning of a three layer copper sample was carried out in a confocal setup at the XRF beamline of the Brazilian Synchrotron Light Laboratory. The sample was irradiated with photons having a fixed monochromatic energy of 8969 eV, i.e., 10 eV below the K absorption edge of Cu. After the data processing, taking also into account the experimental resolution of the detection system, the results show oscillation patterns that depend on the different compounds of copper. This outcome was verified by using a complementary Partial Least-Squares (PLS) analysis.The results are relevant since they allowed observing the presence of different oxide-layers, impossible to discriminate with conventional geometries of irradiation. They also permit the characterization of a compound present at a particular depth of the sample with micrometer resolution using a typical SDD system.