High resolution measurement of Kb emission spectra in Mn metal and Mn compounds

S. LIMANDRI; G. TIRAO; M TORRES DELUIGI; S. CEPPI; G. STUTZ; J.A. RIVEROS

Campinas

Congreso; XVIII Reunión Anual de Usuarios del LNLS; 2008

LNLS

In transition metals, X-ray Kb spectra consist of main lines(Kb1;3, Kb5) and satellite lines whose origin are related to spincoupling of 3p and 3d electrons and ligand type. Althoughchanges in Mn–Kb spectra and its relation with the chemicalenvironment has been quite studied in the last decades [1-5], synchrotrons and the development of high resolution spectrometersallows to improve the information quality obtainedabout absorption and emission process.In Mn–compounds, with unpaired 3d electrons, the Kbemission is split into a doublet composed of the main Kb1;3line and a less intense , low energy Kb0 satellite. At the highenergy side of the main line, the satellite line Kb00 (traditionallycalled "cross-over" transitions) can be observed. The Kb00relative position respect to Kb5 contains information about theligand type, and its intensity is related to the number of ligandatoms and its bond length. The Kb5 band arises from transitionsthat fills the 1s atomic orbital from molecular orbitals(MO) with electronic population of metal 3p and/or 4p andligand 2p or 2s. Kb5 line shifts can be used to determine theoxidation state [4].In this work, Kb emission spectra of manganese compoundswith different oxidation states are analyzed in orderto characterize the dependence of energy lines and intensitieswith oxidation state, net spin in the valence band and ligandtype.