High Resolution Kb Spectroscopy and Chemical Environment in Cr Compounds

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

Campinas

Otro; Activity Report LNLS 2007; 2007

LNLS

The transitions from the valence band to the 1s level generate chemically sensible emission lines due to changes in the molecular orbital in different compounds. The electronic configuration of chromium in ground state is [Ar]3d54s1, where the 3d orbital have five unpaired electrons. The 3p-1s transition originates the Kb1,3 line. At higher energies of Kb1,3 line, its appear two structures of lines Kb" and Kb5. The Kb" lines are originated in the molecular orbital 2sL transition to atomic orbital 1s, so its energy has information of the type atom that is bound to the metal, whereas its intensity is related to the number of ligand atoms and the distance of them to the metal. This transition could be considered as an interatomic transition between the ligand and the principal atoms. On the other hand the Kb5 band is formed by transitions from the molecular orbital with population of 3d and/or 4p of the metal and 2p or 3p of ligand to the 1s atomic orbital of metal. The Kb5 band energy shift could be used to determine the oxidation state. In this work, the Kb emission spectra of chromium in compounds with different oxidation states are analyzed to characterize the dependence of the line energy and line width with the oxidation state.