https://doi.org/10.1140/epjb/e2005-00057-y
The effect of iron doping in La0.8Sr0.2Fe0.05Co0.95O3-δ perovskite
1
Department of Nuclear Chemistry, Eötvös Loránd
University, Pázmány P. s. 1/a, Budapest 1117, Hungary
2
Research Group for Nuclear Methods in Structural Chemistry, Hungarian
Academy of Sciences, Hungary
3
Laboratoire de Physique de l'État Condensé, UMR CNRS 6087,
Université du Maine, 72085 Le Mans Cedex 9, France
4
Institute for Chemical Technology of Inorganic Materials,
Johannes Kepler University, Altenbergerstrasse 69, 4040 Linz, Austria
5
Institute of Nuclear Research of the Hungarian Academy of Sciences,
4001 Debrecen, POB 51, Hungary
Corresponding author: a hentes@ludens.elte.hu
Received:
9
September
2004
Revised:
5
November
2004
Published online:
15
March
2005
La0.8Sr0.257Fe0.05Co0.95O3-δ perovskite
is investigated by 57Fe transmission and emission Mössbauer
spectroscopy, X-ray diffraction, AC magnetic susceptibility and
magnetotransport measurements. Temperature dependence of the 57Fe
Mössbauer isomer shift, quadrupole splitting, magnetic hyperfine field,
line broadening, and relative spectral area is presented in a detailed
manner for La0.8Sr0.257Fe0.05Co0.95O3-δ. The oxidation state of iron is determined to be Fe3+, and the
presence of preferential electronic charge compensation Fe3+ → Fe4+ over that of Co3+ → Co4+ is excluded. Relaxation
of iron magnetic moments reflected by the 57Fe Mössbauer spectra of
La0.8Sr0.257Fe0.05Co0.95O3-δ are
interpreted as evidence for the existence of superparamagnetic like Co
clusters and a corresponding cluster glass magnetic phase formed below
K.
PACS: 75.47.Gk – Colossal magnetoresistance / 75.50.Lk – Spin glasses and other random magnets / 76.80.+y – Mössbauer effect; other gamma-ray spectroscopy
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005