57Fe Mössbauer and infrared studies of the system Co1−x Cd x Fe2O4

Abstract

Mossbauer and infrared studies were made on samples of the ferrite system Co1−xCdxFe2O4x=0.0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1. Mossbauer spectra were taken at room temperature. The spectra of the samples withx≤0.7 showed well defined Zeeman patterns and they have been analyzed with two components, one due to A-site Fe3+ ions, and the other due to B-site Fe3+ and Fe2+ ions. The pattern due to B-site appeared to be composite and an explanation is given. The spectra withx=0.9 and 1 showed only a quadrupole splitting. The effect of cadmium substitution on the various hyperfine interactions has been discussed and the cationic distribution has been deduced for all values ofx. Far infrared spectra of the ferrite samples in the range 200–700 cm−1 were reported. Four bands were observed: the high frequency bandv1 is assigned to tetrahedral complexes, and the low frequency bandv2 to octahedral complexes, a small bandv3 is due to Co2+-O2− complexes andv4 is assigned to the lattice vibration of the system. The splitting occurred in thev1 andv2 bands atx=0.9 and inv2 atx=1, indicating the presence of Fe2+ ions in octahedral sites.