# A XANES study of mixed-valence transition metal oxides and rare earth alloys

Sankar, G and Sarode, PR and Rao, CNR (1983) A XANES study of mixed-valence transition metal oxides and rare earth alloys. In: Chemical Physics, 76 (3). pp. 435-442.

 PDF sdarticle1.pdf Restricted to Registered users only Download (490kB) | Request a copy

## Abstract

Energies of the 1s → 3d. 1s → 4s and 1s → 4p transitions of Mn, Fe and Co in a series of oxides have been obtained from X-ray absorption near-edge structure (XANES). Bivalent metal oxides do not show separate features in XANES due to the two oxidation states of the metal, but the spectroscopic transition energies. $E_\gamma$: as well as the 3d-4s and 3d-4p energy differences. $\delta$E, increase smoothly with the oxidation number of the metal or its effective atomic charge, q. The variation of transition energies as well as $\delta$E values with q is best described by the parabolic relation. $E_\gamma (or \deltaE) = aq + bq^2$. Mixed-valence cerium and ytterbium alloys distinctly show transitions due to the valence states in the XANES.

Item Type: Journal Article Chemical Physics Elsevier Science Copyright of this article belongs to Elsevier Science Division of Chemical Sciences > Solid State & Structural Chemistry Unit 10 Jun 2008 19 Sep 2010 04:44 http://eprints.iisc.ac.in/id/eprint/13734