Valence-state mixing and separation in SmBaFe2O5+w

No Thumbnail Available

Access rights

© 1999 American Physical Society (APS). This is the accepted version of the following article: Lindén, J. & Karen, P. & Kjekshus, A. & Miettinen, J. & Pietari, T. & Karppinen, Maarit. 1999. Valence-state mixing and separation in SmBaFe2O5+w. Physical Review B. Volume 60, Issue 22. 15251-15260. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.60.15251, which has been published in final form at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.60.15251.
Final published version

URL

Journal Title

Journal ISSN

Volume Title

School of Chemical Technology | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

1999

Major/Subject

Mcode

Degree programme

Language

en

Pages

15251-15260

Series

Physical Review B, Volume 60, Issue 22

Abstract

A mixed-valence state, formally denoted as Fe2.5+, is observed in the 300 K Mössbauer spectra of the most reduced samples of SmBaFe2O5+w. Upon cooling below the Verwey-type transition temperature (TV≈200K), the component assigned to Fe2.5+ separates into a high-spin Fe3+ state and an Fe2+ state with an unusually low internal field. The separation of the mixed-valence state at TV is also confirmed by magnetic susceptibility measurements and differential scanning calorimetry. A model is proposed which accounts for the variation of the amount of the mixed-valence state with the oxygen content parameter w.

Description

Keywords

mixed-valence states, Fe2.5+, SmBaFe2O5+w

Other note

Citation

Lindén, J. & Karen, P. & Kjekshus, A. & Miettinen, J. & Pietari, T. & Karppinen, Maarit. 1999. Valence-state mixing and separation in SmBaFe2O5+w. Physical Review B. Volume 60, Issue 22. 15251-15260. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.60.15251.