Room and low-temperature magnetic characterization of Cr doped CoFe2O4 nanostructures

Abstract

The macroscopic magnetism in nanoparticulated systems is the consequence of numerous contributions, ranging from the spatial arrangement of nanoparticles to their intrinsic nanostructure. Understanding and unraveling these temptations is essential to scientifically and technologically introduce nanomaterials. In the present work, we investigate how the magnetic properties of Co ferrite can be significantly ameliorated by Cr substitution. At first, applied the co-precipitation strategy to synthesize stoichiometric Co ferrite nanoparticles followed by the Cr substitution to achieve CoCrxFe2-xO4 (0 ≤ x ≤ 1) nanoparticles. The phase and structural analysis by X-ray diffraction identified the formation of spinel structure with the Fd-3m space group. An increasing behaviour in X-ray density with Cr substitution in Co ferrite has been observed due to lattice contraction. Field-emission scanning electron microscopic images confirmed that the particle size ranged from 14 to 17 nm. Room temperature magnetic investigations showed that the magnetic coercivity of the synthesized nanoparticles increased up to 40% Cr substitution, followed by a monotonic decrease in the magnetic properties. Low-temperature magnetic properties were carried out for 40% Cr substituted Co ferrite. The increase in saturation magnetization with a reduction in temperature followed Bloch's law, and the trend of temperature-dependent coercivity was confirmed with Kneller's law.