Synthesis and properties of Mn-Zn ferrite ferrofluids

A Mn-Zn ferrite ferrofluid is produced by chemical synthesis. Two different types of ferrofluids, according to the type of carrier liquid, are synthes ized: an aqueous cationic ferrofluid and a surf acted hydrocarbon-based one . Ferrite particles are characterized by using several techniques: X-ray di ffraction, transmission electronic microscopy, IR-spectroscopy, thermogravi metry, magnetization measurements and chemical analysis. Particles size dep ends on the synthesis parameters and can be partly controlled by choosing t he type of the coprecipitating base. Increasing of the Zn concentration lea ds to smaller size of synthesized particles, as well as effects the content of associated water. Magnetization of the ferrofluid significantly decreas es when the degree of Zn substitution exceeds 0.5. (C) 1999 Kluwer Academic Publishers.