Magnetic and Mössbauer Spectral Study of Core/shell Structured Fe/Au Nanoparticles
Fe/Au nanoparticles have been chemically synthesized through a reverse micelle reaction and investigated by both conventional and synchrotron-based X-ray diffraction and by magnetic and Mössbauer spectral studies. The powder X-ray diffraction patterns reveal both the presence of crystalline α-iron and gold and the absence of any crystalline iron oxides or other crystalline products. First-order reversal curves, along with the major hysteresis loops of the Fe/Au nanoparticles, have been measured as a function of time in order to investigate the evolution of their magnetic properties. The iron-57 Mössbauer spectra of both uncoated iron nanoparticles and the Fe/Au nanoparticles have been measured at 78 and 295 K and indicate that two major iron-containing components are present, namely, the expected α-iron and the unexpected amorphous Fe 1-xB x alloy; several poorly crystallized ordered iron(III) oxide components as well as paramagnetic iron(II) and iron(III) components are also observed. These results indicate that the Fe-core/Au-shell nanoparticles synthesized through reverse micelles are far more complex than had been believed.
S. Cho et al., "Magnetic and Mössbauer Spectral Study of Core/shell Structured Fe/Au Nanoparticles," Chemistry of Materials, vol. 18, no. 4, pp. 960-967, American Chemical Society (ACS), Feb 2006.
The definitive version is available at http://dx.doi.org/10.1021/cm0522073
Alfred P. Sloan Foundation
American Chemical Society
National Science Foundation of Belgium
Ministere de la Region Wallonne
National Science Foundation (U.S.)
University of California (System)
Keywords and Phrases
Power X-ray Diffraction Patterns; Reverse Micelles; Crystallization; Gold; Iron Alloys; Iron Oxides; Micelles; Mössbauer Spectroscopy; Synthesis (Chemical); X Ray Powder Diffraction; Nanostructured Materials; X-rays -- Diffraction
International Standard Serial Number (ISSN)
Article - Journal
© 2006 American Chemical Society (ACS), All rights reserved.