Synthesis, characterization and magnetic properties of La3+ added Mg–Cd ferrites prepared by oxalate co-precipitation method

Nanosized powders of Mg–Cd–La ferrite synthesized by oxalate co-precipitation method using high purity sulphates are presented. The powder has been characterized by X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The phase identification of powder reveals biphasic nature of materials. The lattice constant, X-ray and physical density, porosity, crystallite size, site radii and bond length were directly affected by addition of rare earth ion (La3+) in Mg–Cd ferrite. The crystallite size of the samples lies in the range 25.67–30.55 nm. FT-IR spectra show two absorption bands in the frequency range from 3.5 × 104 to 8.0 × 104 m−1 which are attributed to stretching vibration of tetrahedral and octahedral complex Fe3+–O2− respectively. The addition of La3+ alters the characters of powder and decreases the grain size which suppresses the abnormal grain growth. The addition of La3+ resulted increase in saturation magnetization, remnant magnetization, 4πMs and coercivity. Coercivity shows size dependent behavior. Such results are promising ones for high frequency applications.

Research highlights▶ XRD study shows orthoferrite phase in addition to cubic spinel phase by La3+addition in Mg–Cd ferrite. ▶ The lattice constant, grain size, are found to decrease where as X-ray density, porosity increases and are higher than that of pure Mg–Cd ferrite. ▶ Crystallite size of the samples lies in the nanoparticle range. The grain size (0.36–0.66 μm) increases with increase in Cd2+ content and is smaller than pure samples as well as reported by ceramic method. ▶ The absorption band υ2 shift to higher frequency side and also broadens, which confirms the occupancy of La3+ ions on octahedral B site. ▶ The saturation magnetization and magnetic moment increases up to x = 0.4 and further decreases. ▶ The coercivity and saturation magnetization shows size dependant behavior. ▶ The reduction in grain size and crystallite size as compared to pure samples improves the structural and magnetic properties.