Synthesis and magnetic properties of Fe3O4/helical carbon nanofiber nanocomposites from the catalytic pyrolysis of ferrocene

High purity Fe₃O₄/helical carbon nanofiber composites were obtained on a large scale by the catalytic pyrolysis of ferrocene in the presence of tin powder at 500°C over 12 h. The sizes of Fe₃O₄ nanoparticles are 35–65 nm in size, and the diameters of the helical carbon nanofibers range from 40–70 nm. The shapes and compositions of the nanocomposites are simply controlled by adjusting the reaction temperatures. On the basis of the obtained experimental results the formation of the helical Fe₃O₄/carbon nanofiber composites was investigated and discussed. The magnetic hysteresis loop of the products shows ferromagnetic behavior with saturation magnetization (M _s), remanent magnetization (M _r) and coercivity (H _c) values of ca. 29.8 emu/g, 9.6 emu/g and 306.6 Oe, respectively.