The study of ⁵⁷Fe Mössbauer spectra for La_0.7Sr_0.3FeO_3−δ with different structure

Abstract

Samples of Lw.7Sro.3Fe03 -6 were obtained by sintering the precursor prepared by the Polyethylene Glycol (PEG) method. The measurements of XRD and 57Fe Mossbauer spectra showed that the heat treatment of the precursor at different temperatures leads to phase transformations from the orthorhombic to the cubic and finally to the rhombohedral phase, to an increase of average grain size, and to changes of the electronic states of the Fe ions. It, was thought that in the perovskite oxides the conditions of synthesis or treatment may have an important influence on structure and properties by adjusting the valence state or/and introducing oxygen vacancies.