Preparation and characterisations of magnetic nanofluid of zinc ferrite for hyperthermia

Abstract

Zinc ferrite (ZnFe2O4) nanoparticles were synthesised by using solution gelation and the self-combustion technique. The resulting zinc ferrite nanoparticles were structurally analysed by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometry for structural, morphological and magnetic properties, respectively. The XRD pattern shows that the prepared sample has a spinel monophasic cubic structure, and the broadening of X-ray peaks indicates the nanocrystalline size of the particles to be on the order of 13 nm. FE-SEM analysis shows spherical-type grains and confirms the nanocrystalline nature with an average grain size of 24 nm. The energy-dispersive X-ray analysis spectrum indicates the purity of the sample and the presence of the desired ions in good proportions. The magnetisation–field strength (M–H) hysteresis loop shows enhanced magnetisation with the superparamagnetic nature of zinc ferrite nanoparticles compared with previous literature reports. The saturation magnetisation value (M s) was estimated to be 23·25 emu/g. The obtained nanoparticles of zinc ferrite were used to prepare nanofluids with water as a base fluid (2 mg/ml concentration). Magnetic hyperthermia studies were carried out using an induction heating system. The induction heating results show that a small amount (2 mg/ml) of zinc ferrite nanoparticles can achieve a 42°C temperature for 258 s at 4·0 kA/m.