Mossbauer Spectra of Copper Nickel Ferrites

Solid State Laboratory, Chemistry Department, Indian Institute of Technology, Powai, Bombay-400 076

MÖssbauer spectra of the compositions Cu₁- \(x\)Ni\(x\)F_e2O₄(0 ≤ x ≤ 1) have been studied. For x ≤ 0.2, the compounds are tetragonal and the rest are cubic spinels. Cation distribution obtained from the split lines of the MÖssbauer spectra does not agree with that obtained from magnetisation data. The spectra seem to be complicated due_. to the presence of more than one hyperfine field at the B site Fee+ owing to the distorting effect of the Cu²⁺ ion on the A sites. This leads to non-Lorentzian line shapes and excludes straight-forward calculation of cation distribution from relative areas under resonances.