2005/04/13 by Sung‐Jin Cho, Sung-Jin Cho, Juan-Carlos Idrobo +5
Energy · Materials Science · Physics and Astronomy · #Gold and Silver Nanoparticles Synthesis and Applications #Iron oxide chemistry and applications #Magnetic properties of thin films #cond-mat.mtrl-sci
paper · pdf · doi:10.1021/cm0500713
published as Chem. Mater., 17 (12), 3181 -3186, (2005). · 21 pages, 4 figures, Chemistry of Materials, in press
arxiv created 2005/04/13 · openalex publication_date 2005/05/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report the chemical synthesis of Fe-core/Au-shell nanoparticles by a reverse micelle method and the investigation of their growth mechanisms and oxidation-resistant characteristics. The core−shell structure and the presence of the Fe and Au phases have been confirmed by transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Mössbauer spectroscopy, and inductively coupled plasma techniques. Additionally, atomic-resolution Z-contrast imaging and electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) have been used to study details of the growth processes. The Au shell grows by nucleating on the Fe-core surface before coalescing. The magnetic moments of such nanoparticles, in the loose powder form, decrease over time due to oxidation. The less than ideal oxidation resistance of the Au shell may have been caused by the rough Au surfaces. However, in pressed pellet form, electrical transport measurements show that the particles are fairly stable, as the resistance of the pellet does not change appreciably over time.