Synthesis of highly magnetic Mn-Zn ferrite (Mn0.7Zn0.3Fe2O4) ceramic powder and its use in smart magnetorheological fluid

Manganese-zinc ferrite (Mn0.7Zn0.3Fe2O4) powder containing irregular-shaped particles with high saturation magnetization and high magnetic softness was synthesized via solution combustion method. By dispersing these magnetic ceramic particles in silicone oil, a magnetorheological fluid (MRF) was prepared and its magneto-mechanical property was studied. The yield strength ((Y)) exhibited by the MRF increases with increase in applied magnetic field, and a very high value of yield strength of similar to 10.5kPa (at B=1.2T) was observed. The viscosity () of the MRF also increases with B due to increased inter-particle magnetic interaction. The low density, low cost of the precursors and the industrial scalability of the Mn-Zn ferrite powder-production render these powders suitable for large-scale device applications. In addition, the thermal, oxidative and chemical stabilities of these ferrimagnetic oxide ceramics are advantageous for their application in corrosive and high temperature environments.