Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8152645 | Journal of Magnetism and Magnetic Materials | 2018 | 5 Pages |
Abstract
The influence of thermal annealing on the structural and magnetic properties of nanocrystalline La1-xSrxFeO3-γ perovskites with x=0, 0.3, 0.4 and 0.5 was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Mössbauer spectroscopy and magnetization measurements. Samples prepared by a sol gel method were calcined for 4â¯h at 1073â¯K and annealed for 8â¯h at 1273â¯K. XRD data indicate the formation of single phases in all samples, orthorhombic with the space group Pbnm for xâ¯=â¯0.0 and 0.3 and rhombohedral with the space group R3â¾c for xâ¯=â¯0.4 and 0.5. The Mössbauer spectroscopy reveal that the sintering process increase the amount of Fe4+ and decrease the paramagnetic sites. Despite of the XRD data indicating the samples to be single phase, the higher coercivity observed in the samples with xâ¯=â¯0.4 may be associated with the emergence of Sr1-xLaxFe12O19 clusters in the samples. Irreversibility in the measurements of magnetization as a function of temperature was interpreted in terms of a high temperature glass cluster behavior.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
R.B. da Silva, J.M. Soares, José. A.P. da Costa, J.H. de Araújo, A.R. Rodrigues, F.L.A. Machado,