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Permanent Magnetism in Exchange-Coupled Nanocomposites

Published online by Cambridge University Press:  21 February 2011

R. Skomski ,
J. P. Liu  and
D.J. Sellmyer
R. Skomski
Affiliation:
Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, NE 68588-0113, U.S.A
J. P. Liu
Affiliation:
Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, NE 68588-0113, U.S.A
D.J. Sellmyer
Affiliation:
Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, NE 68588-0113, U.S.A
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Abstract

The magnetic properties of permanent magnetic nanocomposites are investigated both experimentally and by model calculations. Rare-earth transition-metal films and nanocomposite thin films containing a L10 hard phase (PtFe) have been prepared by plasma sputtering and heat treatment. By choosing suitable heat-treatment processes a nearly ideal nanostructure and high energy products of up to about 50 MGOe have been achieved for the Fe-Pt system. The behavior of the nanocomposites is discussed in terms of a model applicable to nearly ideal magnets, where there are no pronounced shoulders in the hysteresis loops. Analytic expressions for M(H) are obtained for a number of cases, and it is discussed how the loops depend on the micromagnetic parameters of the involved phases. A novel aspect of magnetic nanostructures is that very small magnetic grains exhibit very large energy products, even if they are intrinsically soft-magnetic.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 577: Symposium H – Advanced Hard and Soft Magnetic Materials , 1999 , 335
Copyright
Copyright © Materials Research Society 1999

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References

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