Synthesis of Highly Dispersed Fe3O4 Submicrometer Spheres in a One-Pot Anion-induced Solvothermal System

A facile, anion-induced, one-pot solvothermal method was successfully developed to prepare two kinds of highly dispersed magnetic Fe3O4 submicrometer spheres at 200°C in 12 h. The diameters of the as-prepared Fe3O4 submicrometer spheres are ~500 and ~200 nm, respectively. With the guidance of OAc − ions, the size and morphology of the Fe3O4 spheres could be well controlled. The saturation magnetization of the Fe3O4 spheres was measured to be 84 and 74 emu/g, respectively. The assembly of tiny precursor nuclei into the Fe3O4 spheres relies on Ostwald ripening. The synthesized Fe3O4 submicrometer spheres show good magnetic response, good water solubility, and uniform size.