Preparation and properties of temperature-sensitive magnetic fluid having Co0.5Zn0.5Fe2O4 and Mn0.5Zn0.5Fe2O4 nanoparticles

Magnetic properties of Co0.5Zn0.5Fe2O4 and Mn0.5Zn0.5Fe2O4 nanoparticles and preparation of temperature-sensitive magnetic fluid are discussed in this paper. Ferrofluids having Co0.5Zn0.5Fe2O4 and Mn0.5Zn0.5Fe2O4 fine particles were prepared by co-precipitation and by ball milling the precipitated fine particles. Ball milling technique was used for coating of the surfactant rather than size reduction. The final cation contents estimated from the prepared powder samples agree with the initial degree of substitution. The powder samples were characterized by XRD, VSM and Mossbauer studies. The precipitated particles were less than 10 nm size and showed FCC spinel structure. Mossbauer studies confirm the single domain nature of the fine particles. Temperature-sensitive ferrofluid having transformer oil as the carrier liquid was prepared by carrier exchange technique. Co0.5Zn0.5Fe2O4 particles can be used for the preparation of temperature-sensitive magnetic fluid with relatively large magnetic volume force.