Structure and Properties of Nanostructured YBa2Cu3O7-δ, BiFeO3, and Fe3O4

The development of new nanostructured materials based on YBa2Cu3O7-delta, BiFeO3, and Fe3O4 compounds is considered. The structure, morphology, and properties of these materials are studied. The possibilities of fabricating YBa2Cu3O7-delta ceramics with given densities from nanopowders in a single stage by an energy efficient method and growing superconducting films of the same composition on a silicon substrate (on a SiO2 layer) are demonstrated. The technique for fabricating BiFeO3 nanopowder, making it possible to obtain nanostructured ceramics without additional accompanied phases commonly forming during BiFeO3 synthesis is developed. Two methods of the single-stage synthesis of Fe3O4 nanopowder are presented: burning of nitrate-organic precursors and the electrochemical three-electrode method in which one of the electrodes, i.e., an anode containing scrap iron and slurry, is used as an expendable material.