Effect of Al3+ substitution on the transport properties of copper ferrite

This study presents the compositional and the temperature-dependent thermoelectric power and dc resistivity measurements on polycrystalline spinel ferrite system: CuAlxFe2-xO4 (x = 0.0, 0.2, 0.4 and 0.6). The probable conduction mechanisms in the system are Fe2+ <-> Fe3+ + e(-) (n-type) at the octahedral sites and Cu2+ <-> Cu1+ + e(+) (p-type) at the tetrahedral sites. The cationic concentrations of Cu1+, Cu2+, ferrous and ferric ions have been deduced from Seebeck coefficients which, in turn, are used to determine the actual cation distribution, oxygen deficiency and to explain the variation and origin of dc resistivity with Al concentration. The Fermi energy, charge carrier concentration and mobility of charge carrier have been determined to explain the charge transport phenomena.