The formation of a layer of Fe3O4 nanoplates between two carbon films

Monodispersed Fe3O4 nanoplates between two carbon films were synthesized by pyrolyzing ferrocene and sodium oxalate in a stainless steel autoclave of 64 mL capacity at 600 °C. The Fe3O4 nanoplates are triangular single crystals, sometimes truncated, with edge lengths ranging from 50 to 100 nm. In an experiment where the pressure of the reaction system was increased, carbon-encapsulated Fe3O4 nanorods were obtained. The inner Fe3O4 nanorods are also single crystal with a diameter ca. 100 nm and lengths up to 1 μm. A possible formation mechanism for the layered structure is proposed based on the experimental results. Magnetic property measurements show that the layered nanoplates display ferromagnetic properties at room temperature.