Magnetic properties of rare earth ion (Sm3+) added nanocrystalline Mg–Cd ferrites, prepared by oxalate co-precipitation method

Nanocrystalline ferrite powder having the general formula Mg1−xCdxFe2O4+5% Sm3+ (x=0, 0.2, 0.4, 0.6, 0.8 and 1.0) was synthesized by chemical oxalate co-precipitation technique. The synthesized powder was characterized by X-ray, IR and SEM techniques. The XRD analysis confirms cubic spinel phase with orthoferrite secondary phase. The lattice constant increases with increase in Cd2+ content (x). It is smaller than that for pure Mg–Cd ferrites. The average crystallite size lies in the range 28.69–32.66 nm. Saturation magnetization and magnetic moment increase with cadmium content up to x=0.4 and decrease thereafter. This is attributed to the existence of localized canted spin. The decrease in saturation magnetization and magnetic moment beyond x=0.4 is due to the presence of triangular spin arrangement on B-site. Coercivity and remanent magnetization decrease while Y–K angles increase with Cd2+ content. The Sm3+ addition improves the magnetic properties.