The influence of ruthenium on the magnetic properties of γ-Fe2O3 (maghemite) studied by Mössbauer spectroscopy

Helgason, Orn; Greneche, Jean-Marc; Berry, Frank J. and Mosselmans, Frederick (2003). The influence of ruthenium on the magnetic properties of γ-Fe2O3 (maghemite) studied by Mössbauer spectroscopy. Journal of Physics: Condensed Matter, 15(17) pp. 2907–2915.

DOI: https://doi.org/10.1088/0953-8984/15/17/338

Abstract

Ruthenium-doped gamma-Fe2O3 has been synthesized and examined by x-ray powder diffraction, XANES, EXAFS and by Fe-57 Mossbauer spectroscopy. Ruthenium K-edge x-ray absorption spectroscopy shows that ruthenium adopts a fully occupied octahedral site in the spinel related gamma-Fe2O3 structure as Ru4+. The Fe-57 Mossbauer spectra recorded in the presence of a longitudinal magnetic field of 6 T confirmed the octahedral coordination of the tetravalent ions and canting angles for the Fe3+ ions were determined as 24degrees for those in octahedral sites and 33degrees for those in tetrahedral sites. The Fe-57 Mossbauer spectra recorded in situ from ruthenium-doped gamma-Fe2O3 showed parameters typical of maghemite up to 600 K but with a magnetic hyperfine field distribution suggesting an inhomogeneous distribution of ruthenium within particles of varied size around about 15 nm. At 700 K a phase transition from gamma-Fe2O3 to alpha-Fe2O3 was observed and further studies showed the ruthenium-doped alpha-Fe2O3 to have a Morin transition temperature of about 400 K.

Viewing alternatives

Look up in Google Scholar

Metrics

Public Attention

Altmetrics from Altmetric

Number of Citations

Citations from Dimensions
No digital document available to download for this item

Item Actions

Export

About

CORE (COnnecting REpositories)