Magnetically soft nickel-zinc ferrite (Ni0.5Zn0.5Fe2O4) powder with high saturation magnetization was synthesized by solution combustion route using metal nitrates as precursors and glycine as fuel. The particles were found to have irregular morphology. Three different concentrations of magnetorheological fluids (MRFs) were prepared by dispersing 10, 20 and 40 wt% of these particles in thin silicone oil. The behaviours of the MRFs were studied under steady shear conditions at different applied magnetic field strengths (B). The yield strength (tau(Y)) and viscosity (eta) of all the MRFs were found to increase with B and particle fill fraction phi, while the response of the MRFs was strongly influenced by the morphology, microstructure and saturation magnetization of the particles. Owing to the low density of the particles, the observed off-state viscosity is high. However, the excellent thermo-oxidative and chemical stabilities of these magnetic oxide particles than metallic magnetic particles make these MRFs dependable for applications in harsh working environments. In addition, the low cost and feasibility of large scale preparation of these magnetic oxides make these MRFs further attractive for industrial applications. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.