Structure and transport in rare-earth ferrates

The Rare-Earth ferrates REFeO3 (RE = La, Pr, Sm, Gd, Ho) were prepared by the citric acid route. The distortion in the FeO6 octahedron decreased with the decrease in the ionic radii (except for Ho) and the angle between adjacent FeO6 octahedra decreased with the ionic radius of the rare earth. Electrical conductivity showed semiconducting behaviour with a complex dependence of the activation energy on the ionic radii of RE ion. Fast oxygen desorption was observed above 300 °C. No effect of A-site cation on the coefficients of thermal expansion was observed.