Magnetic nanoparticles (NPs) are of interest for use in magnetic hyperthermia. To achieve high efficient NPs as a heating agent, it is important to know the effect of processing parameters on the synthesis, microstructure and magnetic properties of NPs and their relationship with the systems’ specific loss power (SLP). In the present study, zinc cobalt ferrite NPs were precipitated using the co-precipitation method, and calcined at 550, 650 and 750 °C for 1 and 2 h. Then to evaluate their hyperthermia properties, ferrofluids of neat and PEGylated NPs (NPs@PEG) were studied. The analysis of X-ray diffraction (XRD), field emission electron microscopy (FESEM), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), zeta potential and transmission electron microscopy (TEM) were used to characterize the NPs. It was found that the processing parameters had a significant effect on the microstructure, magnetic and hyperthermia properties of the synthesized NPs. With increasing the time and temperature of calcination, particle size and magnetic properties like anisotropic constant, magnetic moment and saturation magnetization increased too. Hyperthermia results showed that the synthesized NPs at 550 °C for 2 h produced more heat than the other samples. It was also found that the concentration of NPs had a great influence on the heat generated by the prepared ferrofluids. Ferrofluids containing 5 mg/ml of NPs synthesized at 550 °C for 2 h had the highest heating efficiency such that the SLP value of NPs and NPs@PEG was 139.3 and 83.6 W/g, respectively.
