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Fabrication of spherical particles with mixed amorphous/crystalline nanostructured cores and insulating oxide shells

Published online by Cambridge University Press:  31 January 2011

J.I. Hong*
Affiliation:
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30126; and Center for Magnetic Recording Research, University of California—San Diego, La Jolla, California 92093
F.T. Parker
Affiliation:
Center for Magnetic Recording Research, University of California—San Diego, La Jolla, California 92093
V.C. Solomon
Affiliation:
School of Materials, Arizona State University, Tempe, Arizona 85287
P. Madras
Affiliation:
School of Materials, Arizona State University, Tempe, Arizona 85287
David J. Smith
Affiliation:
School of Materials and Department of Physics, Arizona State University, Tempe, Arizona 85287
A.E. Berkowitz
Affiliation:
Center for Magnetic Recording Research and Department of Physics, University of California—San Diego, La Jolla, California 92093
*
a)Address all correspondence to this author. e-mail: jhong@gatech.edu
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Abstract

By spark-eroding Fe75Si15B10 in water/ethanol mixtures, spherical particles with nanostructured cores consisting of mixed amorphous and crystalline phases were produced. The relative volume fractions of the amorphous and crystalline phases were dependent on the water/ethanol ratio. In the same process, continuous oxide layers were formed on the particle surfaces. The basic mechanisms responsible for the formation of the surface oxide layers and the core nanostructures were modeled. At frequencies ranging from 1 to 100 MHz, the combination of the core nanostructures and the insulating oxide shells yielded exceptionally low-loss magnetic behavior.

Type
Articles
Copyright
Copyright © Materials Research Society 2008

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References

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