Minimum hysteresis loss and amplified magnetic properties of superparamagnetic Ni–Zn nano spinel ferrite

Abstract

Nanocrystalline NixZn1-xFe2O4 ferrite was prepared using the microwave-assisted sol-gel auto combustion method. The nanocrystalline ferrite was characterized by powder XRD, SEM, FT-IR, VSM, Mossbauer, magnetic and dielectric study. The lattice constant, tetrahedral radius, octahedral radius, anion parameter, average crystalline size, tetrahedral bond length, octahedral bond length, and deviation parameter have been estimated from XRD and compared with standard results. The magnetic properties of the prepared ferrite were studied and parameters like saturation magnetization, magnetic remnant, magnetic moment, coercivity, and SQR were estimated. The effect of substitution on isomer shift and magnetic exchange interaction between octahedral and tetrahedral sites on magnetic properties were discussed from Mossbauer’s study. It was observed that the isomer shift does not vary appreciably with a concentration of nickel in zinc lattice. Moreover, the exchange interaction between Fe3+ ions at tetrahedral and octahedral sites and the doped nickel ions prefer the octahedral sites that strongly favor the magnetic interactions. The temperature dependence AC susceptibility was measured to know the magnetic phase transition. The dielectric constant and tangent loss are high at lower frequencies, decreasing with frequency and finally becoming almost constant. The dielectric constant ε′ was also found to increase with the increase in Ni2+ content.