Synthesis and Characterization of hollow Fe3O4 submicrospheres by a Simple Solvothermal Synthesis

Hollow single crystal Fe3O4 submicrospheres, which exhibit excellent magnetic properties, have been synthesized by a simple solvothermal process. These Fe3O4 particles have nanocrystallites with an average diameter of about 300 nm and are constructed with a hollow sphere structure that has an inside diameter of about 70 nm. The growth of the hollow Fe3O4 submicrospheres involves the cooperation of Ostwald ripening and oriented re-aggregation with increasing reaction time. As the oriented aggregation continues, adjacent nanocrystals fuse together along the (311) direction and the final product is formed as hollow spheres. Optional re-aggregation of the Fe3O4 hollow spheres may happen in the EG and N2H4 center dot H2O solution. The synthesized Fe3O4 particles show different magnetic properties and can be adjustable with morphological variation.