Surfactant-free synthesis and magnetic hyperthermia investigation of iron oxide (Fe3O4) nanoparticles at different reaction temperatures

چکیده مقاله

The effect of reaction temperature (TR, ranging from 40 °C to 80 °C) on magnetic hyperthermia measurements
was investigated in the surfactant-free co-precipitation synthesis of magnetite (Fe3O4) nanoparticles (NPs). The
size, structure and magnetic properties of the synthesized NPs were studied by X-ray diffraction, field-emission
scanning electron microscopy (together with energy dispersive spectroscopy), hysteresis loop and first-order
reversal curve analyses. The investigations showed that all the NP samples were single domain with a superparamagnetic
(SP) feature. After preparing the respective ferrofluids with a concentration of 5 mg/ml (in distilled
water medium) acting as nanoheaters, hyperthermia measurements were performed under an alternating
magnetic field with a frequency of 400 kHz. It was found that TR=60 °C resulted in the maximum specific loss
power (SLP) value of 181 W/g together with an SP fraction of 82%, being a suitable candidate for use in
magnetic hyperthermia. In this case, the resulting saturation magnetization and SP fraction were in the middle of
corresponding values obtained from TR=40 °C and 80 °C. Our results showed that a balance between relatively
high saturation magnetization and low coercive field led to the maximum SLP.