FeVO4 was synthesised by conventional solid state technique. Impedance measurements using a silver electrode were unsuccessful due to a solid state reaction between FeVO4 and Ag, forming α-AgVO3 and α-Fe2O3 at the interface. Impedance measurements, with a platinum electrode, reaffirmed that FeVO4 exhibits semiconductor behaviour in air. In a reducing atmosphere, 5% H2/Ar, high electronic conductivity, from 1 S cm−1 at 300 °C to 2 S cm−1 at 700 °C, was observed with an activation energy of 0.13(1) eV. X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry data determined that the change in electronic conductivity was due to the degradation of the material into FeV2O4 and α-Fe2O3. It is believed that the conduction was due to electron hopping between vanadium d-orbitals. Neither FeVO4 nor FeV2O4 are deemed suitable as anode materials for solid oxide fuel cells, due to redox instability.
- Electronic materials
- Inorganic compounds
- Powder diffraction
Cowin, P. I., Lan, R., Zhang, L., Petit, C. TG., Kraft, A., & Tao, S. (2011). Study on conductivity and redox stability of iron orthovanadate. Materials Chemistry and Physics, 126(3), 614-618. https://doi.org/10.1016/j.matchemphys.2011.01.009