Preparation and investigation of potentiality of different soft ferrites for hyperthermia applications

Water-based ferrofluids of substituted ferrites Fe1−xMnxFe2O4 (0⩽x⩽1) have been prepared by the co-precipitation method and characterized. Particles are superparamagnetic with an average particle size of about 10–12nm. The specific absorption rate (SAR) was measured by calorimetric measurement at a frequency of 300kHz and a field of 10–45kA∕m. The variation of SAR and magnetization of Fe1−xMnxFe2O4 with Mn concentration shows similar dependence. Innocuousness studies of MnFe2O4 ferrofluids to the living cells have been carried out with BHK-21 cells. In vitro studies showed that threshold biocompatible concentration is dependent on the nature of ferrites and coating.