Role of Mg2+ substitution on viscosity and thermal conductivity of nickel ferrite based magnetic fluids

Abstract

The present investigation shows the viscosity and thermal conductivity of Mg2+ substituted nickel ferrite based magnetic fluids of different chemical compositions (Ni1-xMgxFe2O4). The nanoparticles were synthesized using a simple and cost-effective co-precipitation method. The XRD result shows the formation of a cubic spinel structure. SEM analysis confirmed the size of the nanoparticles ranges between 1 µm and 500 nm. The Experimental results show that the viscosity of magnetic fluids of two different volume fractions decreases for the rise in temperature and for the increase in rotations per minute (RPM). The results on thermal conductivity of two different volume fractions of Ni1-xMgxFe2O4 based magnetic fluids exhibit enhanced thermal conductivity than the carrier fluid (transformer oil). The thermal conductivity results were compared with Maxwell’s theoretical prediction and experimental models for confirmation.