Switchable hardening of a ferromagnet at fixed temperature
- Creators
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Silevitch, D. M.
- Aeppli, G.
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Rosenbaum, T. F.
Abstract
The intended use of a magnetic material, from information storage to power conversion, depends crucially on its domain structure, traditionally crafted during materials synthesis. By contrast, we show that an external magnetic field, applied transverse to the preferred magnetization of a model disordered uniaxial ferromagnet, is an isothermal regulator of domain pinning. At elevated temperatures, near the transition into the paramagnet, modest transverse fields increase the pinning, stabilize the domain structure, and harden the magnet, until a point where the field induces quantum tunneling of the domain walls and softens the magnet. At low temperatures, tunneling completely dominates the domain dynamics and provides an interpretation of the quantum phase transition in highly disordered magnets as a localization/delocalization transition for domain walls. While the energy scales of the rare earth ferromagnet studied here restrict the effects to cryogenic temperatures, the principles discovered are general and should be applicable to existing classes of highly anisotropic ferromagnets with ordering at room temperature or above.
Additional Information
Copyright © 2010 National Academy of Sciences. Edited by Sidney Nagel, University of Chicago, and approved December 14, 2009 (received for review September 16, 2009). Published ahead of print January 29, 2010. The work at the University of Chicago was supported by DOE Basic Energy Sciences under Grant No. DEFG02-99ER45789, while work in London was supported via the United Kingdom Engineering and Physical Sciences Research Council. D.M.S. acknowledges use of the central facilities of the NSF Materials Research Science & Engineering Center. Author contributions: D.M.S., G.A., and T.F.R. designed research; D.M.S. and T.F.R. performed research; D.M.S. analyzed data; and D.M.S., G.A., and T.F.R. wrote the paper. The authors declare no conflict of interest. This Direct Submission article had a prearranged editor.Attached Files
Published - PNAS-2010-Silevitch-2797-800.pdf
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Additional details
- PMCID
- PMC2840359
- Eprint ID
- 46931
- Resolver ID
- CaltechAUTHORS:20140707-163025699
- Department of Energy (DOE)
- DE-FG02-99ER45789
- Engineering and Physical Sciences Research Council (EPSRC)
- Created
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2014-07-09Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field