Spin canting phenomenon in cadmium doped cobalt ferrites, CoCdxFe2-xO4 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), synthesized using sol-gel auto combustion method

Synthesis of non-collinear (spin canted) ferrites having the formula, CoCd (x) Fe2 -aEuro parts per thousand x O (4) (x = 0 center dot 0, 0 center dot 2, 0 center dot 4, 0 center dot 6, 0 center dot 8 and 1 center dot 0), has been carried out using the sol-gel auto combustion method. The ferrite samples show an interesting magnetic transition from Neel to Yafet-Kittel configuration, as the Cd2 + concentration is increased beyond x = 0 center dot 4. The FT-IR spectra confirm the formation of the metal oxide bond as they exhibit two frequency bands in the range of similar to 595 cm (-aEuro parts per thousand 1) and similar to 450 cm (-aEuro parts per thousand 1), corresponding to the tetrahedral and the octahedral stretching vibrations of the metal oxide, respectively. The structural evolutions of the nanophase investigated using powder X-ray diffraction (XRD) technique show that the average crystallite size is similar to 35 nm. The magnetic studies reveal that the saturation magnetization, M (s) , increases up to x = 0 center dot 4 and decreases when the value of x is > 0 center dot 4. It is proposed that the incorporation of Cd2 + ion takes place into the tetrahedral sites and up to x = 0 center dot 4, Neel's model is followed. But for x > 0 center dot 4, canting of spins occurs, as explained by Yafet-Kittel (Y-K) model. The d.c. resistivity decreases as a function of temperature, indicating semiconducting nature of the ferrites and the positive value of Seebeck coefficient establishes p-type conduction behaviour for all the ferrite samples.