Synthesis and magnetic properties of Co1-xZnxFe2O4+γ nanoparticles as materials for magnetic fluid hyperthermia
Abstract
Nanoparticles of the single spinel phase Co1-xZnxFe2O4+γ of mean size 3 nm - 23 nm, as determined by X-ray diffraction analysis, were synthesized by the co-precipitation method followed by a temperature treatment. Magnetic studies carried out in the range of 4.5 - 550 K revealed gradual transition from ferrimagnetic to superparamagnetic to paramagnetic behaviour depending on the composition and particle size.
The observed behaviour indicates a broad distribution of volume sizes of the nanoparticles. Particular importance can be ascribed to the composition of x = 0.6 where the observed transition temperature to the paramagnetic state at 310 - 334 K suggests applicability of this material for magnetic fluid hyperthermia in a self controlled regime.