Syntheses and Characterization of Core-Shell Iron-Based Magnetic Nanoparticles Coated by Carbon*

In recent years, there has been a growing interest in synthesizing of novel iron-based nanoparticles and nanocomposites with high efficiency of thermal energy transfer suitable for use in magnetic fluid hyperthermia. Here we investigate structural and magnetic properties of Carbon-coated ferromagnetic (Fe-Fe3O4)@C “core-shell” nanocomposites synthesized by a solid-phase pyrolysis (SPP) of Iron phthalocyanine (FeC32H16N8) molecules. This product of pyrolysis additionally annealed at 250°C under oxygen media produces (Fe3O4) shell on Fe nanoparticles. We conducted a thorough investigation of structural and magnetic properties of these materials using X-ray diffraction (XRD), Raman spectroscopy, magnetometry, electron paramagnetic and ferromagnetic resonances (EPR, FMR). The characteristics of magnetic heating of water-based solutions with different concentrations of synthesized nanocomposites under the influence of an external magnetic field have been studied. The magnetic characteristics such as saturation magnetization and coercivity as well as the specific absorption rate (SAR) make these materials attractive for magnetic hyperthermia applications.