Exchange Coupling in Nano-Textured SmCo5/Fe and Ni/CoFe2O4 Permanent Magnets

Technical Report · Fri Mar 09 00:00:00 EST 2018

DOI:https://doi.org/10.2172/1430911· OSTI ID:1430911

Baker, A. A. ^[1]; Worthington, M. W. ^[1]; Baker, S. E. ^[1]; Lee, J. I. ^[1]; Orme, C. A. ^[1]; Kuntz, J. ^[1]; van Buuren, T. ^[1]; McCall, S. K. ^[1]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

The widespread use of magnets in actuators, generators and sensors has driven materials optimization research for decades, aiming to match the desirable properties of high remnant magnetization, and a high coercive field, to maximizing the energy product. Currently, Dy-doped NdFeB offers the best values, but its low operating temperature and the supply challenges of Dy are driving a search for alternatives. One such notion is the development of exchange coupled magnets, which combine a high coercivity (hard) magnet with a less coercive (soft) material which has a higher magnetization and no RE content. The strength of this approach is that exchange coupling between the two phases maintains the anisotropy in the soft material at high coercive fields. The result is a composite material with high energy density that can, theoretically, exceed the performance of the pure hard phase for specific architectures. In this experiment we studied two candidate materials for an exchange coupled magnet: NiFeB coated SmCo₅, and Ni@CoFe₂O₄ core shell nanoparticles, using element-specific XMCD hysteresis loops to investigate the magnetisation reversal process in these composite systems.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 1430911
• Report Number(s): LLNL-TR-747579
• Country of Publication: United States
• Language: English

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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
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