FE-57 MOSSBAUER AND INFRARED STUDIES OF THE SYSTEM CO1-XCDXFE2O4

Mossbauer and infrared studies were made on samples of the ferrite system Co1-xCdxFe2O4, x = 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 with x less than or equal to 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 with x = 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 of x. Far infrared spectra of the ferrite samples in the range 200-700 cm(-1) were reported. Four bands were observed: the high frequency band nu(1) is assigned to tetrahedral complexes, and the low frequency band nu(2) to octahedral complexes, a small band mu(3) is due to Co2+-O2- complexes and nu(4) is assigned to the lattice vibration of the system. The splitting occurred in the nu(1) and nu(2) bands at x = 0.9 and in nu(2) at x = 1, indicating the presence of Fe2+ ions in octahedral sites.