Magnetic and electronic properties of vanadium-substituted magnetite VxFe3−xO4 thin films

Abstract Distribution of transition-metal ions and the related magnetic and electronic properties of vanadium-substituted magnetite (V x Fe 3− x O 4 ) thin films have been investigated. The V x Fe 3− x O 4 films were found to maintain cubic structure up to x =1.0 with little change in the lattice constant. Analysis on 2p core-level XPS spectra of V indicates that V ions exist with a valence of +3 mostly and small +2 population in the compound. Analysis on the Mossbauer spectra indicates that V ions mainly substitute the octahedral sites. VSM data reveal that the magnetization of the V x Fe 3− x O 4 films increases at low x compared to that of Fe 3 O 4 and then gradually decreases as x increases. The coercivity of the samples is found to increase with x , attributable to the increase of anisotropy by the substitution of V 2+ (d 3 ) ions at the octahedral sites.