Application of Rietveld method to the structural characteristics of substituted copper ferrite compounds

A series of ferrite samples of the chemical composition Cu 0.7 (Zn 0.3-xMg x)Al 0.3Fe 1.7O4 [x=0.05, 0.1, 0.15 and 0.2], prepared by ceramic technique at 1000°C, were found to have cubic spinel structure. On applying the full pattern fitting of Rietveld method using FullProf program, the exact coordinates of atoms, the unit cell dimensions, the atom occupation factors, isotropic temperature factors, the profile shape parameters as well as the interatomic distances have been determined. It was found that the lattice parameter decreases with increasing the Mg content. Also the variation of the cation distribution has been discussed on the basis of site preference, size and valence of the substituting cations. The low isotropic microstrain values obtained during the refinement process may be attributed to the method of the preparation in which the samples after the last sintering were treated by annealing.