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+ → Fe 4+ 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 T ≈65 K.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics