Abstract
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 alpha-AgVO3 and alpha-Fe2O3 at the interface. Impedance measurements, with a platinum electrode, reaffirmed that FeVO4 exhibits semiconductor behaviour in air. In a reducing atmosphere, 5% H-2/Ar, high electronic conductivity, from 1 S cm(-1) at 300 degrees C to 2 S cm(-1) at 700 degrees 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 alpha-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.
Original language | English |
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Pages (from-to) | 614-618 |
Number of pages | 5 |
Journal | Materials Chemistry and Physics |
Volume | 126 |
Issue number | 3 |
Early online date | 1 Feb 2011 |
DOIs | |
Publication status | Published - 15 Apr 2011 |
Keywords
- ceramics
- electronic materials
- inorganic compounds
- oxide
- powder diffraction
- oxide fuel cells
- electrochemical properties
- electrical conductivity
- oxidation
- systen
- temperature
- anode
- performance
- transition