LAUSR

Abstract Nanoparticles of gadolinium (Gd 3+ ) and cobalt (Co 2+ ) doped manganese spinel ferrites have been synthesized by micro-emulsion method. TGA (Thermo gravimetric analysis), XRD (X-ray diffraction), magnetic hysteresis, FTIR (Fourier transform infrared spectroscopy) and dielectric measurements were done to study the variation in manganese ferrite with Co 2+ and Gd 3+ substitution and their effect on lattice parameter and other parameters such as saturation magnetization (Ms), coercivity (Hc) and remanance (Mr). The phase development identified by XRD showed the cubic nature of the fabricated material. The lattice parameter increased due to larger ionic radii of gadolinium and cobalt as compared to iron and manganese. Magnetic properties showed a definite S shaped hysteresis loop at room temperature for all compositions. Overall, the magnetic parameters were increased. This increase could be explained by substitution of Fe 3+ ions with Gd 3+ ions. Gd 3+ ions have very high value of magnetic moment due to seven unpaired electrons. FTIR spectra exhibited two major frequency bands and confirmed cubic spinel structure. The dielectric analysis showed decrease in dielectric loss and dielectric constant with the increase in substitution and frequency.