2D-Maps of Cu Paintings by Resonant Inelastic X-ray Scattering (RIXS) with Multivariate Methods

SÁNCHEZ, HÉCTOR JORGE; JOSE ROBLEDO; JUAN JOSÉ LEANI

Cordoba

Simposio; International Symposium on Radiation Physics (ISRP-14); 2018

Universidad Nacional de Cordoba

Recent works have shown that the species of an element can be determined by inspecting the fine structure of the RIXS emission peaks [1,2]. One of the most important characteristics of RIXS, using SDD systems with low-resolution in energy, is the possibility of combining this tool with all of the experimental techniques and geometries associated to XRF spectroscopy. Combinations of this RIXS tool with total reflection, depth-profiling analysis using grazing incidence geometries and confocal setups have been already reported [3-6].In this work, we present results of RIXS-2D maps in different samples containing Cu paints. The measurements were carried out at the XRF beamline @ Brazilian Synchrotron Light Laboratory (LNLS, Campinas). The samples were irradiated with photons having a fixed monochromatic energy just below the K absorption edge of copper. After a simple data processing, involving multivariate methods, the fine structure of the RIXS spectra show oscillation patterns that depend on the different Cu chemical states.The studied samples are interesting since they present a rich contrast of compounds of the same element, being difficult to analyze using conventional/time-consuming spectroscopic techniques, as the absorption ones. Using this novel RIXS tool, we produced fast and reliable maps/images showing the different species of the element of interest, providing atomic environment information at micrometer level in a 2D regime.Examples of applications of this RIXS tool for chemical state determinations in Cu paintings are presented and discussed.Keywords: 2D-Maps, RIXS, Multivariate Methods.[1] H.J. Sánchez, J.J. Leani, M.C. Valentinuzzi and C.A. Pérez, Journal of Analytical Atomic Spectrometry 26, 378 (2011).[2] J. J. Leani, H. J. Sanchez, M. C. Valentinuzzi and C. A. Pérez, X-Ray Spectrometry 40, 254 (2011).[3] J.I. Robledo, J.J. Leani, A.G. Karydas, A. Migliori, C.A. Pérez, H.J. Sánchez, Analytical Chemistry, ID: AC-2017-04624s.R1. (2018).[4] J.J. Leani, J.I. Robledo, H.J. Sánchez, X-Ray Spectrometry, doi: 10.1002/xrs.2782 (2017).[5] J.J. Leani, R.D. Pérez, J.I. Robledo, H.J. Sánchez, Journal of Analytical Atomic Spectrometry 32, 402 (2017).[6] J. Robledo, H.J. Sánchez, J.J. Leani and C. Pérez, Analytical Chemistry 87, 3639 (2015