Mössbauer Studies of Superexchange Interaction in Tetragonal CuFe2O4

CuFe2O4 has been studied by Mössbauer spectroscopy and X‐ray diffraction. The crystal is found to have a tetragonal spinel structure with the lattice constants a0 = (5.805 ± 0.005) Å and c0 = (8.669 ± 0.005) Å. The iron ions are in ferric Fe3+ states. The temperature dependence of the magnetic hyperfine fields at 57Fe nuclei at the tetrahedral (A) and octahedral (b) sites is analyzed by the Néel theory of ferrimagnetism. The intersublattice superexchange interaction is found to be antiferromagnetic with its strength of JA—B = — 19.5kB while intrasublattice superexchange interactions are ferromagnetic with their strengths of JA—A = 3.1kB and JB—B = 4.4kB.