Influence of Co2+ on structural and electromagnetic properties of Mg–Zn nanocrystals synthesized via co-precipitation route

Co-precipitation method was used to synthesize the nanoparticles of cobalt substituted zinc–magnesium ferrites having formula “Mg0.6−0.5xZn0.4−0.5xCoxFe2O4” where 0.00≤x≤0.250.00≤x≤0.25. Fabricated samples were annealed at 750 °C for 6 h. The cubic spinel structure of Mg0.6−0.5xZn0.4−0.5xCoxFe2O4 nanocrystals was confirmed by Fourier transformed infra-red (FTIR) and X-ray diffraction (XRD). Lattice parameter, crystalline size, cell volume, X-ray density, bulk density and porosity were also determined using XRD data. Lattice parameter exhibits overall decreasing trend (0.824–0.817 nm) with cobalt content; it is due to the substitution of cobalt (having smaller ionic radii) with magnesium and zinc ions. Cation distribution among A and B sites were studied by FTIR spectrum. Vibrating sample magnetometery (VSM) was used to investigate magnetic properties of as prepared nanoparticles. Coercivity exhibits the inverse relation to crystalline size. Lowest value of coercivity (47.722 Oe) was obtained for the sample having x=0.15. Dielectric constant, dielectric loss and dielectric tan loss were inversely related with the frequency.