Optimized Mn0.5Zn0.5Fe2O4 nanoflowers based magnetic fluids for potential biomedical applications

Magnetic nanoclusters of the nanoflower type exhibit unique physical and magnetic properties as compared to their constituent nanoparticles due to the intra-cluster interactions. The present work highlights the maneuvering of Mn0.5Zn0.5Fe2O4 nanoflower-based magnetic fluids for possible biomedical applications. The formation mechanism of the nanoflowers and the strategies to control the dimensions of the nanoflowers are described in detail. The nanoflowers are characterized using different structural and magnetic techniques: XRD, TEM, DLS, U/ SAXS, BET, VSM, and induction heating. The size of nanoflowers is tuned from 107 to 218 nm using the hydrothermal route by controlling the reaction time. The core-shell cluster model is developed to fit the SAXS data to retrieve the size of the nanoflowers as well as their constituent particles. It is seen that the cluster sizes obtained from various techniques are complementary to each other. This is a first attempt of its kind to show that the size of nanoclusters determined by different techniques (TEM, DLS, and U/SAXS) are comparable. Also, the size and size distribution of constituent particles within a cluster/flower complement each other (XRD, TEM, U/ SAXS and Magnetization). The results are explained using the surface area and porosity of nanoflowers determined using the BET technique. The dispersion of nanoflowers can be used for magnetic fluid hyperthermia as well as for other applications where a large surface area-to-volume ratio is desirable.