CuFe 2 O 4 has been studied by Mo È ssbauer spectroscopy and X-ray diffraction. The crystal is found to have a tetragonal spinel structure with the lattice constants a 0 (5.805 AE 0.005) # e and c 0 (8.669 AE 0.005) # e. The iron ions are in ferric Fe 3 states. The temperature dependence of the magnetic hyperfine fields at 57 Fe nuclei at the tetrahedral (A) and octahedral (B) sites is analyzed by the Ne  el theory of ferrimagnetism. The intersublattice superexchange interaction is found to be antiferromagnetic with its strength of J AÀB À19X5k B while intrasublattice superexchange interactions are ferromagnetic with their strengths of J AÀA 3X1k B and J BÀB 4X4k B .

No abstract

No abstract

No abstract

has been studied by means of Mössbauer spectroscopy and x-ray diffraction. The crystal is found to have a cubic spinel structure with the lattice constant . The iron ions are in ferric states. The temperature dependences of the magnetic hyperfine fields at the nuclei at the tetrahedral (A) and octahedral (B) sites are analysed using the Néel theory of ferrimagnetism. The inter-sublattice superexchange interaction is found to be antiferromagnetic with a strength of while the intra-sublattice superexchange interactions are ferromagnetic with strengths of and . The Debye temperatures of the tetrahedral and octahedral sites are determined to be and , respectively.