Fe and Fe3O4 nanowires have been synthesized by thermal decomposition of Fe(CO)5, followed by heat treatments. The Fe wires are formed through the aggregation of nanoparticles generated by decomposition of Fe(CO)5. A core-shell structure with an iron oxide shell and Fe core is observed for the as-prepared Fe wires. Annealing in air leads to the formation of Fe2O3/Fe3O4 wires, which after heat treatment in a N2/alcohol atmosphere form Fe3O4 wires with a sharp Verwey [Nature (London) 144, 327 (1939)] transition at 125 K. The Fe3O4 wires have coercivities of 261 and 735 Oe along the wire axis at RT and 5 K, respectively. The large increase of coercivity at 5 K as compared to RT is due to the increase of anisotropy resulting from the Verwey transition.
J. Yang et al., "Large Scale Growth and Magnetic Properties of Fe and Fe₃O₄ Nanowires," Journal of Applied Physics, American Institute of Physics (AIP), Apr 2006.
The definitive version is available at http://dx.doi.org/10.1063/1.2172208
Materials Science and Engineering
United States. Department of Energy
Keywords and Phrases
Annealing; Coercive Force; Ferromagnetic Materials; Iron; Iron Compounds; Metal-Insulator Transition; Nanotechnology; Nanowires; Pyrolysis
Article - Journal
© 2006 American Institute of Physics (AIP), All rights reserved.