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 160 emug, 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 20 h, 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 - Fe2 O3. © 2005 American Institute of Physics.