High field magnetization of the colloidal Mn–Zn ferrite

Abstract The magnetic properties of a hydrocarbon based colloid (stabilized by oleic acid) of polydisperse chemically co-precipitated Mn 0.5 Zn 0.5 Fe 2 O 4 particles are discussed in the paper. Two fractions are separated from an initial ferrofluid sample by centrifugation. X-ray diffraction measurements show the crystal structure of the particles and a broadened shape of the diffraction lines. Mean particle diameters 6.2 nm (the light fraction) and 9.7 nm (the heavy one) were determined by TEM measurements. The magnetization of the colloids is measured by VSM up to 12 T. A significant slope in the magnetization curves in the high field region is displayed for both samples in the temperatu…