Chemical effects in high resolution Kb spectrum in Mn compounds

LIMANDRI S.; TIRAO G.; CEPPI S.; STUTZ G.; RIVEROS J. A.

Campinas, Brasil

Congreso; Reunión Anual de Usuarios del LNLS; 2008

Laboratorio Nacional de Luz Sincrotron

Kb spectrum in Mn metal and various Mn compounds were measured at the D12A-XRD1 beamline using an X-ray high resolution spectrometer [1]. The instrumental resolution at the Mn-Kb1,3 energy was calculated to be 1.9 eV. This improved energy resolution allow chemical effect-induced enhancement and line shift of emission lines to be examinated with high accuracy. Relative intensities, linewitdths and line shifts were investigates in Mn compunds exhibiting different oxidation states (0,+2,+3,+4,+5,+7) and different type of ligand atoms (O, F, S). It was found that the Kb2,5 and Kb´ energy related to the Kb1,3 is very sensitive to the oxidation state. These para meters could be used to determine oxidation states with accuracy higher tha using the Kb1,3 energy, as suggested by other authors [2,3]. The observed energy shift of the Kb´´ satellite line was measured to be shifted about several eV from the Kb2,5 line, depending on the type of ligand atom in the investigated Mn compounds, as previously found by Bergmann et al [5]. The results found in this work prove that high resolution Kb fluorescence can be considered as a good technique to characterize chemical environment. [1] G. Tirao, G. Stutz, C. Cusatis. J. Synchrotron Rad. 11, 335 (2004). [2] S. Gamblin, D. Urch. J. Elect. Spec. Rel. Phenom. 113,179 (2001). [3] J. Iihara, T. Omori, K. Yoshihihara, K. Ishii. Nucl. Instr. Meth. B 75, 32 (1993). [4] K. Tsutsumim H. Nakamori, K. Ichikawa. Phys. Rev. B, 13, 929 (1976) [5] U. Bergmann, C. Horne, T. Collins, J. Workman, S. Cramer. Chem Phys. Lett. 302, 119 (1999).