Mechanochemical synthesis of MnZn ferrite nanoparticles suitable for biocompatible ferrofluids

JACOBO SILVIA; MERCEDES ARANA ; PEDRO MENDOZA ZÉLIS; PAULA G. BERCOFF ; GUSTAVO A. PASQUEVICH

CERAMICS INTERNATIONAL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2016 vol. 42 p. 1545 - 1551

0272-8842

Mn0.4Zn0.6Fe2O4 nanoparticles (NPs) were synthesized by the mechanochemical method, starting from elemental oxides. Structural andmagnetic properties of the NPs were investigated by X ray diffraction (XRD), vibrating sample magnetometry (VSM) and both scanning andtransmission electron microscopy (SEM and TEM). XRD measurements show that MnZn ferrite is already present after 15 min of milling. Aftermilling for 120 min, the resulting powder is almost completely single-phase without the need of any thermal treatment. Magnetization curves forsamples with different milling times show saturation magnetizations ranging from 12.2 emu/g ?after 15 min to 50.3 emu/g ?after 120 min.Coercive field and remanent magnetization are negligible for all samples, in agreement with a superparamagnetic behavior. NPs with mean size of8 nm were separated by centrifugation and were coated with chitosan for the preparation of a ferrofluid, which showed good stability for 12 h.The Intrinsic Loss Parameter (ILP) of this fluid indicates that the mechanochemical method can be a good alternative for the synthesis of the usualFe-oxides ferrofluids used in hyperthermia.