Properties of Zinc-based Magnetic Nanoparticle Prepared by Co-Precipitation Technique*

This research presents the structural and viscoelastic analysis of Zinc-based ferrite magneto rheology fluid (MR) (ZnFe₂O₄) nanoparticle synthesized by chemical co-precipitation technique. The structural properties revealed a single-phase cubic spinel with narrow diffraction peaks confirming the particle at nano-dimension with an average crystallite size of 9.02 nm. The Energy Dispersive X-ray Spectroscopy of ZnFe₂O₄ nanoparticle revealed 100% pure ZnFe₂O₄ indicating that there is no presence of an impurity in the fluid. SEM image revealed fairly porous layers showing that the particles are well compacted with no surface damage or fracture; the morphology showed closely parked nanoparticles devoid of pores and cavity. The magneto viscoelastic performance of the fluid was evaluated under the magnetic influence of 0, 0.475 T, and 1.076 T and shear rates of 100 s^-1, 200 s^-1 and 300 s^-1. The viscoelastic properties show various degrees of response with the application of different magnetic fields. The figure of merit increases as the shear rate increases; the result indicates improved shear thinning characteristics as well as non-Newtonian behavior at the figure of merit of the order 10⁶ when the shear rate is 300 S^-1.