Magnetic hyperthermia properties of iron oxide nanoparticles: The effect of concentration

We investigated the effect of concentration on magnetic hyperthermia properties of Fe3O4 nanoparticles (NPs). The NPs were synthesized by co-precipitation method at 80 degrees C. Scanning electron microscope image showed that the mean diameter of NPs is about 18 nm. The XRD pattern indicated that the sample is pure Fe3O4 with spinel structure and the FT-IR spectroscopy confirmed formation of metal-oxygen bonds in the octahedral and tetrahedral spinel sub-lattice which further confirmed crystalline structure of the sample. The hyperthermia property of Fe3O4 NPs was investigated via an induction heater generating alternating magnetic field with frequency of 92 kHz. The temperature rise (Delta T) of suspension in the AC magnetic field was studied on different concentrations of NPs and the specific absorption rate (SAR) was obtained from Box-Lucas equation and linear fitting of Delta T-time curve. The results showed that the Delta T sharply increases with increasing the NPs concentration while the SAR remains almost constant.