Spatially Resolved Resonant-Raman Scattering Spectroscopy

H. J. SÁNCHEZ; J. J. LEANI; C. A. PÉREZ

Campinas

Congreso; RAU XXI; 2011

When atoms are irradiated by X ray photons dierent kinds of interactions takeplace: the photon can be absorbed by the photoelectric eect or can suer a Rayleighor Compton scattering. However, under resonant conditions, other low probabilityinteractions can occur. One of these interactions is the resonant Ra- man scattering(RRS). The X ray resonant Raman scattering is an inelastic scat- tering processwhich presents fundamental dierences compared to other scattering interactions be-tween X rays and atoms; when the energy of the incident photon ap- proaches frombelow to the absorption edge of the target element, a strong resonant behavior takesplace contributing to the attenuation of X rays in matter. It is well known thatthe use of synchrotron radiation in trace analysis by x-ray uorescence (SRXRF)allows to reduce detection limits and to improve sensitivities. The intrinsic charac-teristics of synchrotron radiation (high intensity, polarization, natural collimation,etc.) and the construction of dedicated sources of synchrotron light make possi-ble to improve detection limits for trace elements in several orders of magnitude.The special characteristics of SRXRF combined with the structural information ofRRS provide a unique opportunity of analysing oxidation state in several types ofsamples with spatial resolution. A special type of application is the analysis of bio-logical samples, which includes surveys related to the human body. In particular thestudy of dental mineralized tissues. In this work we present preliminary results ofmicro-RRS analysis with spatial resolution of dental tissues. Linear scannings werecarried out covering dierent areas of a dental sample including dental calculus, i.e.,root, dentine, enamel, and tartar. The experimental data required a complex anddeep analysis. The prelimi- nary results show clear variations of the RRS structuresaccording to the position of irradiation opening the possibility of a precise structuralanalysis via Raman scattering combined with micro-XRF.Acknowledgements: This work was partially supported by the LNLS (Campinas. Brazil).