Mössbauer studies on Zn-substituted iron molybdate

Mössbauer spectra of Fe_2−yZn_yMoO₄ spinel ferrites were recorded in their paramagnetic state. Paramagnetic Mössbauer spectra of all the samples show broad absorption peaks due to the presence of Fe²⁺ and Fe³⁺ ions on both sites (A and B) of the spinel lattice. All the spectra have been fitted with four doublets, using a least squares fitting program. The isomer shift and quadrupole splitting values show that Fe_A²⁺, Fe_A³⁺, Fe_B³⁺ and Fe_B^2.5+ ions are present. Fe_B^2.5+ represents the presence of the Fe²⁺ and Fe³⁺ ions on the B-sites, which take part in charge hopping. The results of electrical resistivity and magnetic measurements support charge hopping between Fe²⁺ and Fe³⁺ ions on B-sites.