Magnetic properties of rare earth ion (Sm~(3+)) added nanocrystalline Mg-Cd ferrites, prepared by oxalate co-precipitation method

摘要

Nanocrystalline ferrite powder having the general formula Mg_(1-x)Cd_xFe_2O_4+5% Sm~(3+) (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 Cd~(2+) 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 Cd~(3+) content. The Sm~(3+) addition improves the magnetic properties.