Electric and Magnetic Properties of the Strontium Ferrates

Abstract

A series of strontium ferrate compositions ranging from SrFeO2.7 to SrFeO3.0 have been produced by equilibration at oxygen pressures ranging from 0.2 to 855 atm. The stoichiometric composition SrFeO3.0 exhibits a simple cubic perovskite structure (a=3.850 Å). Ceramic disks of this material are conductive (ρ≈10−3 Ω·cm) and their temperature dependence is characteristic of metallic conduction. Magnetic measurements indicate that SrFeO3.0 is antiferromagnetic below 130°K. With increasing oxygen deficiency, specimens show increased cell constants and eventually tetragonal distortion. Decrease in the Néel temperature and increased resistivity accompany these changes.