New aqueous magnetic fluids

New aqueous magnetic fluids constituted of nickel-zinc ferrite particles ar e synthesized using a soft chemical approach. Ferrofluids and solid particl es are characterized using several techniques : chemical analysis, X-ray di ffraction, transmission electron microscopy, infrared spectroscopy, and mag netization measurements. The stability of the aqueous magnetic fluids is studied as a function of pH and their magnetization is measured as a function of the degree of zinc su bstitution in the mixed ferrite particles, (C) 1999 Elsevier Science B.V. A ll rights reserved.