Mossbauer studies of Co0.5CdxFe2.5-xO4 (0.0 ≤ x ≤ 0.5) ferrite

In the present work, we have studied the magnetic environment of Fe atoms in Cd-doped cobalt ferrite using Mossbauer spectroscopy. A series of six samples with Co0.5CdxFe2.5-xO4 compositions (0.0 <= x <= 0.5) was prepared by sol-gel technique and then investigated by X-ray diffraction at room temperature and Mossbauer spectroscopy measurements in the transmission geometry at 78 K. Results of the XRD measurements indicate that all samples exhibit a single-phase cubic spinet structure. The analysis of the Mossbauer spectra shows a decrease in hyperfine magnetic field decreases at A and B site on increasing the doping of Cd ions. The appearance of the paramagnetic doublet at x = 0.5 clearly indicates that A-B super-exchange decreases due to dilution of the sub-lattice by Cd ions. The isomer shift values calculated from the fitting of the Mossbauer spectra clearly indicate that the resolved sextets in studied samples are due to Fe3+ ions only. (c) 2008 Elsevier B.V. All rights reserved.