Magnetic and rheological characterization of novel ferrofluids

A new type of magnetic fluid containing silica-coated magnetic nanoparticles has been synthesized. The particles are produced by a flame synthesis and have been dispersed in an oily medium to obtain the magnetic fluid. By means of magnetic and rheological investigations the basic properties of these fluids were determined. It could be seen, that the fluids show the well known paramagnetic behavior of ferrofluids with a small hysteresis due to the large domain size of the magnetic particles. Moreover strong dependencies of the rheological functions on magnetic field strength could be observed.