Synthesis, structural, magnetic, and cytotoxic properties of iron oxide coated iron/iron-carbide nanocomposite particles

Abstract

Iron/iron-carbide nanocomposite particles with surface coating of spinel iron oxide were synthesized by thermal decomposition of iron pentacarbonyl [Fe(CO)5] in various atmospheres of argon, methane, and acetylene at a temperature of 257°C. The microstructure, composition, magnetic properties, thermal stability of as-synthesized particles, and the effects of subsequent heat treatment were investigated. The synthesized nanoparticles exhibited a maximum magnetization of 160emu∕g, which was twice that of commonly used spinel iron oxide nanoparticles. After heating in an acidic solution with a pH value of 5 at 60°C for 20h, the nanocomposite particles retained 90% of their initial magnetization. In addition, x-ray diffraction and Mössbauer investigation indicated that the pyrolysis of Fe(CO)5 under different atmospheres resulted in the formation of crystalline iron carbide. It is noted that only Fe was reported to be formed in the literature using the pyrolysis of Fe(CO)5 under an argon atmosphere. Preliminary cytotoxicity assay suggested that the synthesized nanoparticles had comparable biocompatibility to γ-Fe2O3.