Tuning specific absorption rate of Mn ferrite nanoparticles synthesized by a thermal decomposition method with different Mn concentrations

A thermal decomposition method is used to synthesize monodisperse Mn ferrite nanoparticles (NPs) by changing Mn concentration from 0.1 to 0.8 mmol. The effects of Mn concentration on structural, compositional, morphological, magnetic, and hyperthermia properties are investigated. Transmission electron microscopic images show that the morphology of the NPs changes from flower-like to polygonal with increasing the Mn concentration. The saturation magnetization reaches a maximum value of 48.32 emu/g and a minimum value of 11.09 emu/g with changing the Mn concentration, whereas the coercivity value decreases from 12.6 to 5.3 Oe. The first-order reversal curve (FORC) analysis enables the estimation of superparamagnetic contribution of the Mn ferrite NPs in the range of 21-59.5%. The highest specific absorption rate (SAR) value is obtained to be 385.37 W/g for Mn0.1Fe2.9O4 NPs with the maximum superparamagnetic contribution using a manganese concentration of 0.4 mmol.