First order reversal curve analysis of cobalt-nickel ferrite

In this paper Co1-xNixFe2O4 in which x ranging from 0.0 to 1.0 with 0.2 intervals was prepared with different particle size using a co-precipitation method. A single phase cubic spinel structure with an average crystallite size between 24 and 34 nm was obtained. X-ray diffraction, fourier transform infrared spectroscopy, field emission scanning electron microscopy and vibration sample magnetometer were used to characterize the samples. The energy dispersive X-ray analysis was in good agreement with the nominal composition. It was found that the functional groups of Co-Ni spinel ferrite were formed during the combustion process. It was found that by substitution of nickel cation in cobalt ferrite, the saturation magnetization and the coercivity decreased from 52.70 emu/g and 1673 Oe to 22.11 emu/g and 134 Oe, respectively. First order reversal curves were employed to map the magneto-static interactions and coercivity distributions as a function of nickel concentration. Adding nickel shifts the switching field distribution to the lower field thereby softening the samples. The ratio of reversibility increases with an increase in nickel content due to increase in the percentage of super-paramagnetism.