Synthesis of Mn-Zn Ferrite Nanoparticles for Temperature Sensitive Magnetic Fluid

Abstract

The main aim of this thesis is to prepare stable, magnetic fluid using Mn-Zn ferrite nanoparticles transformer cooling applications. In the present work magnetic nanoparticles MnXZn(1-X)Fe2O4 (where x = 0, 0.2, 0.4, 0.6, 0.8,1) were successfully synthesized by Chemical Coprecepitation method. Experimental conditions have been established to prepare superparamagnetic, single phase Mn-Zn ferrite nanoparticles with desired chemical, physical and magnetic properties. By using oleic acid as surfactant, sterically stabilized extra pure kerosene based magnetic fluid is being produced. As-synthesized magnetic nanoparticles were characterized by X-ray diffraction (XRD), Transmission electron microscope (TEM), Vibrating sample magnetometer (VSM) and thermogravimetric (TGA) analysis. From the x-ray analysis, it is clarify evidenced that nanoparticles are crystallized into the well known inverse spinel structure. The peak broading is a clear indicative of formation of ultra small nanoparticles, which was further confirmed by transmission electron microscopy. Superparamagnetic nature of nanoparticles is confirmed via VSM measurement. TGA study confirms the monolayer coating on the surface of the nanoparticles which is essential for their stability in magnetic fluids. The magnetic nanoparticles produced here can be used in heat transfer devices.