Production, structure and magnetic properties of nanocomposites based on the perovskite phase LaFeO3

Abstract

The phase relations in the La2O3–Fe2O3 system at 1300 °C were studied in the whole concentration range by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The samples were prepared with a concentration step of 1–5 mol %. The isothermal cross-sections of the La2O3–Fe2O3 phase diagram at 1300 °C are characterized by the presence of three single-phase (A–La2O3, LaFeO3, Fe2O3), two two-phase (A–La2O3+LaFeO3, LaFeO3+Fe2O3) regions. The composition corresponding to the perovskite phase is 49 mol % La2O3–51 mol % Fe2O3. Nanocomposites based on the perovskite phase (LaFeO3) were obtained by the Pechini method and heterogeneous precipitation from nitrate solutions. Solutions of La3+ nitrates, which were obtained by dissolving lanthanum oxide with a content of the main component of 99.99 % in nitric acid. The influence of the production method on the microstructure, morphology, and magnetic properties of nanopowders (LaFeO3) was studied. According to XRD, infrared spectroscopy, SEM, and TEM, the synthesized perovskite LaFeO3 is single-phase with a particle size of 50–60 nm. The morphology of powder particles primarily depends on the method of material synthesis. The powder showed ferrimagnetic magnetic properties and had a specific magnetization 0.2 and 0.15 emu/g.