Abstract

Au-coated Fe nanoparticles have been prepared by using a reverse micelle method through reduction of an aqueous solution. Characterizations have been carried out over time to probe the oxidation of Fe. Immediately after synthesis, the samples exhibit metallic conduction and a negative magnetoresistance, consistent with the presence of α-Fe. The temperature dependence of magnetization displays a maximum at a blocking temperature of around 150 K. After a period of 1 month, the samples exhibit insulating behavior, indicating the oxidation of the Fe core. Mössbauer spectroscopy indicates the presence of an α-Fe component and a broad distribution of local environments.

Department(s)

Chemistry

Keywords and Phrases

Metallic Conduction; Nanoparticles; Reverse Micelle Method; Zero-field Cooling (ZFC); Coercive Force; Giant Magnetoresistance; Hysteresis; Iron; Magnetic Moments; Magnetization; Micelles; Mössbauer Spectroscopy; Oxidation; Reduction; SQUIDs; Superparamagnetism; Synthesis (Chemical); Transmission Electron Microscopy; Transport Properties; X Ray Diffraction Analysis; Nanostructured Materials

Library of Congress Subject Headings

Iron
Mössbauer spectroscopy
Nanoparticles

International Standard Serial Number (ISSN)

218979

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2004 American Institute of Physics (AIP), All rights reserved.

Included in

Chemistry Commons

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