Magnetization behaviour of Fe3O4–water and γ-Fe2O3–water magnetic nanofluids

Abstract

Magnetic nanofluids are colloids that contain magnetic nanoparticles dispersed in a base fluid. In the presence of the external magnetic field, they can be magnetized and manipulated. Moreover, their thermophysical properties may be tuned. Therefore, it is important to investigate the magnetization behaviour of them. For this purpose, magnetization behaviours of magnetite (Fe3O4)-water and maghemite (γ-Fe2O3)-water which are commonly used in the available literature were investigated by a vibrating sample magnetometer (VSM). Various samples with different volume concentrations for Fe3O4-water (1 and 2%) and γ-Fe2O3-water (1.1 and 2.2%) nanofluids were used in the measurements. The results indicated that γ-Fe2O3-water magnetic nanofluid has higher saturation magnetization values than Fe3O4-water magnetic nanofluid. The measurements also pointed out that as the volume concentration increases, the magnetization of both magnetic nanofluids increases as well.