Abstract
Polycrystalline samples of Mg0.5Zn0.5−xCoxFe2O4 (0 ≤ x ≤ 0.5) with x varying from 0.0-0.5 synthesized by sol-gel auto ignition method. The X-ray diffraction analysis with Retvield refinement reveals the formation of single phase cubic spinel structure. The frequency dependent of real part of dielectric constant has been measured at room temperature and at 100 °C by using an ac impedance analyzer. Except x = 0.5, an increase in the dielectric constant is observed with increase in Co2+ substitution. Magnetic response has been seen by vibrating sample magnetometer (VSM) at room temperature. The saturation magnetization (MS) and coercivity (HC) increase with increasing the Co2+ substitution. The cation distribution estimated by Mössbauer spectroscopy shows that Co2+ and Mg2+ ions have their preference towards octahedral B site, on the other hand Zn2+ ions preferentially occupy tetrahedral A site, whereas Fe3+ ions are randomly distributed over A- and B-site. The as obtained results indicated that the substitution of Co2+ has brought the significant changes in the structural, electrical and magnetic properties of as prepared Mg-Zn-Co multioxide nanocrystals.