Magnetic and Transport Properties of Nanocomposite Fe/Fe₃₋δO₄ and Fe₃₋δO₄ Films Prepared by Plasma-enhanced Chemical Vapour Deposition

Abstract

Reflective, pinhole-free Fe/Fe3O4 and Fe3−δO4/Fe2O3 nanocomposite films were obtained by reacting iron pentacarbonyl, Fe(CO)5, in an inductively-coupled radio frequency glow discharge reactor. The conductivity of the Fex/(Fe3O4)1−x (x > 7%) composite films exhibits metallic characteristics and the conductivity decreases as the α-Fe content decreases. The metal-to-insulator transition temperature of the Fex/(Fe3O4)1−x (x ∼0.07) films shifts to a higher temperature as compared with Fe3−δO4 due to the increased conductivity from α-Fe. The magnetization versus temperature (M-T) curves show the transition temperature ranging from 95 to 136 K, corresponding to the Verwey temperature, which is dependent on the film composition. The Fe3−δO4 film exhibits a negative magnetoresistance of about 4% and 8% at room temperature and 80 K, respectively.

Department(s)

Materials Science and Engineering

Second Department

Physics

Third Department

Chemistry

Sponsor(s)

United States. Department of Energy

Keywords and Phrases

Alpha Iron; Chemical Vapor Deposition; Composition and Phase Identification; Magnetic Phase Boundaries; Thin Films

International Standard Serial Number (ISSN)

0022-3727

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2005 Institute of Physics - IOP Publishing, All rights reserved.

Publication Date

01 Apr 2005

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