Study on the Effect of Mno2 as Sintering Additive in Structural, Magnetic and Electrical Properties of Solid-State Derived Ni0.8Zn0.2Fe2O4

Abstract

Ni-Zn ferrites have been synthesized with varying MnO2 as sintering aid as well as enhancer in magnetic property. The influence of MnO2 additive on the properties of Ni-Zn ferrites was studied by the conventional ceramic method (solid oxide mixing followed by calcination). The results showed that MnO2 does not form a visible second phase while the added concentration was restricted to 0−0.6 weight%. The average grain size, sintering density and gradually decrease with the increase of the MnO2 content. And the DC resistivity continuously increases with the increase of MnO2 content. The saturation magnetization (magnetic moment in unit mass) first increases slightly when mass fraction of MnO2 is less than 0.4% MnO2, and then gradually decreases with increasing the MnO2 mass fraction due to the exchange interaction of the cations. When the excitation frequency is less than 1 MHz, the power loss (Pcv) continuously increases with increasing the MnO2 content due to the decrease of average grain size. However, when the excitation frequency exceeds 1 MHz, eddy current loss gradually becomes the predominant contribution to Pcv. The present investigations reports the effect of additive MnO2 in varying amount i.e. 0.0%, 0.2%, 0.4% and 0.6% on the structural, magnetic and electric properties of NI0.8ZN0.2Fe2O4 prepared by solid oxide mixing method. The powders were calcined at 950ᵒC for 4hrs, XRD analysis conducted. After the confirmation of phases, powders were pressed into pellet. The pellet of different composition were sintered at different temperature and characterized for apparent porosity, bulk density and B-H loop using Magneta. For the phase formation, the pellets were characterized by using XRD and for the microstructure analysis, the pellets were characterized by using FESEM. DC resistivity, magnetic properties are affected by addition of MnO2