Magnetic Properties of Iron Oxide Nanoparticles with Different Geometries

<br/>The functional hybrids based on iron oxide nanoparticles are interesting for multimode imaging and synergistic cancer therapies. In this research, we optimized morphologies as hexagonal, cubic, spherical, and star-shaped. We synthesized them using a thermal decomposition process, optimizing parameters as organic solvents batch time residence and different temperatures. The HR-TEM images show homogeneous and dispersed nanoparticles with sizes between 10 and 120 nm. The XRD patterns contain peaks associated with the spinel structure type (Fd3m) characteristic of Fe₃O₄ (magnetite, JCPDS File No. 19-0629). Magnetic studies were performed at different temperatures, finding the highest saturation magnetization (Ms) 68.24 emu/g at 300K by the star-shaped geometry. The relaxivity studies indicate that they induce T₂responses according to their size and morphology. We propose specific geometries and surface coordination with various moieties to increase the response for biomedical applications