Synthesis, characterization and magnetoresistance properties study of magnetite thin films by electroless plating in aqueous solution

Polycrystalline half-metallic Fe3O4 films with 1 μm in thickness were synthesized on glass substrates directly by electroless plating in aqueous solution at 90 °C without heat treatment. The films have single pure spinal phase structure and the well-crystallized columnar grains grow perpendicularly to the substrates, as revealed by XRD, XPS and SEM. At room temperature, the films exhibit negative magnetoresistance (MR) ratio of about −5.1%, which is ascribed to intergranular tunneling of spin polarized electrons of Fe3O4. The resistivity R of the films with 1 μm in thickness at room temperature is about 5.2 × 10−1 Ω cm. The cation distribution and the arrangement of the magnetic moments of the plated Fe3O4 ferrite thin films are different from that of the bulk materials, which is likely to be one of the reasons for the modification of R and MR properties.

► A modified electroless plating method to synthesize Fe3O4 thin films is proposed. ► The MR, magnetic and cation distribution properties of the films are focused. ► At RT the MR of the films exhibit negative MR ratio and the value is about −5.1%. ► The cation distribution of the films is different from that of the bulk materials.