Application of Mn x Fe 1- x Fe 2 O 4 ( x = 0-1) Nanoparticles in Magnetic Fluid Hyperthermia: Correlation with Cation Distribution and Magnetostructural Properties

Optimization of manganese-substituted iron oxide nanoferrites having the composition Mn Fe Fe O ( = 0-1) has been achieved by the chemical co-precipitation method. The crystallite size and phase purity were analyzed from X-ray diffraction. With increases in Mn concentration, the crystallite size varies from 5.78 to 9.94 nm. Transmission electron microscopy (TEM) analysis depicted particle sizes ranging from 10 ± 0.2 to 13 ± 0.2 nm with increasing Mn substitution. The magnetization ( ) value varies significantly with increasing Mn substitution. The variation in the magnetic properties may be attributed to the substitution of Fe ions by Mn ions inducing a change in the superexchange interaction between the A and B sublattices. The self-heating characteristics of Mn Fe Fe O ( = 0-1) nanoparticles (NPs) in an AC magnetic field are evaluated by specific absorption rate (SAR) and intrinsic loss power, both of which are presented with varying NP composition, NP concentration, and field amplitudes. Mn Fe Fe O exhibited superior induction heating properties in terms of a SAR of 153.76 W/g. This superior value of SAR with an optimized Mn content is presented in correlation with the cation distribution of Mn in the A or B position in the Fe O structure and enhancement in magnetic saturation. These optimized Mn Fe Fe O NPs can be used as a promising candidate for hyperthermia applications.