Magnetic properties of nanoparticles determine their performance in magnetic hyperthermia

A process of heating SPM NPs by magnetization reversal effects induced under exposure to an external oscillating magnetic field. For example, hyperthermia induced in SPM NPs can be used to locally heat and thus destroy cancer cells. The mechanism of magnetic hyperthermia is not fully understood, despite multiple previous theoretical and experimental studies. Rosensweig developed the first theoretical approach, in which the specific absorption rate (SAR) produced by hyperthermia in diluted SPM ferrofluids is attributed to Neel and Brown relaxation processes. At the same time, for ́ particles ≥25 nm in size, ferromagnetic or FiM heat release is ascribed to hysteresis losses.18 This separation of relaxation and hysteresis losses has been subsequently criticized by Carrey and co-workers, who proposed a more comprehensive theoretical framework that combined Stoner−Wohlfarth-based theories, linear response theories, and equilibrium functions, intending to explain the SAR produced by magnetic NPs of any size. Later, Vallejo-Fernandez and co-workers concluded that the susceptibility losses are negligible and the heat is mostly generated by hysteresis loss. Despite the large amount of SAR data found in the literature, none of the models have been confirmed experimentally due to complex contributions of the colloidal parameters, such as anisotropy constant, particle volume, and viscosity of the medium, involved in magnetic hyperthermia mechanisms. Despite the large amount of SAR data found in the literature, none of the models have been confirmed experimentally due to complex contributions of the colloidal parameters, such as anisotropy constant, particle volume, and viscosity of the medium, involved in magnetic hyperthermia mechanisms. If you are looking for high quality, high purity and cost-effective Fe3O4, or if you require the latest price of Fe3O4, please feel free to email contact mis-asia.

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