Hybrid high-temperature nanostructured magnets

David J. Sellmyer, J. Zhou, H. Tang, R. Skomski

Research output: Contribution to journalConference article

2 Citations (Scopus)

Abstract

The hysteretic behavior of two-phase permanent magnets for high-temperature applications is examined. A variety of systems have been synthesized and investigated, including Sm-Co-Cu-Ti bulk magnets, SmCo5:Cu-Ti thin-film materials, and mechanically milled Sm-Co-Zr magnets. The hybrid character of the material leads to very high room-temperature coercivities, between 30.2 and 43.6 kOe, and to the survival of a comparatively large part of the coercivity at high temperatures (12.3 kOe at 500°C for SmCo6.5Cu0.8Ti0.3). The coercivity reflects the structure and chemical composition of the material. When ferromagnetic grains are separated by a ferromagnetic boundary phase, the boundary phase acts as a pinning center, but when the grain-boundary phase has a comparatively low Curie temperature, the high-temperature magnetism of the system is that of a weakly interacting ensemble of magnetic particles. In spite of some residual paramagnetic exchange coupling, which is discussed in this work, this mechanism enhances the coercivity.

Original languageEnglish (US)
Pages (from-to)U5.8.1-U5.8.12
JournalMaterials Research Society Symposium - Proceedings
Volume674
StatePublished - Dec 1 2001
EventApplications of Ferromagnetic and Optical Materials, Storage and Magnotoelectronics - San Francisco, CA, United States
Duration: Apr 16 2001Apr 20 2001

Fingerprint

Coercive force
coercivity
Magnets
magnets
Phase boundaries
Temperature
Exchange coupling
High temperature applications
Magnetism
Curie temperature
permanent magnets
Permanent magnets
chemical composition
Grain boundaries
grain boundaries
Thin films
room temperature
thin films
Chemical analysis

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Hybrid high-temperature nanostructured magnets. / Sellmyer, David J.; Zhou, J.; Tang, H.; Skomski, R.

In: Materials Research Society Symposium - Proceedings, Vol. 674, 01.12.2001, p. U5.8.1-U5.8.12.

Research output: Contribution to journalConference article

Sellmyer, DJ, Zhou, J, Tang, H & Skomski, R 2001, 'Hybrid high-temperature nanostructured magnets', Materials Research Society Symposium - Proceedings, vol. 674, pp. U5.8.1-U5.8.12.
Sellmyer, David J. ; Zhou, J. ; Tang, H. ; Skomski, R. / Hybrid high-temperature nanostructured magnets. In: Materials Research Society Symposium - Proceedings. 2001 ; Vol. 674. pp. U5.8.1-U5.8.12.
@article{4adc679a2b91476e8fc6b679ff79bdc4,
title = "Hybrid high-temperature nanostructured magnets",
abstract = "The hysteretic behavior of two-phase permanent magnets for high-temperature applications is examined. A variety of systems have been synthesized and investigated, including Sm-Co-Cu-Ti bulk magnets, SmCo5:Cu-Ti thin-film materials, and mechanically milled Sm-Co-Zr magnets. The hybrid character of the material leads to very high room-temperature coercivities, between 30.2 and 43.6 kOe, and to the survival of a comparatively large part of the coercivity at high temperatures (12.3 kOe at 500°C for SmCo6.5Cu0.8Ti0.3). The coercivity reflects the structure and chemical composition of the material. When ferromagnetic grains are separated by a ferromagnetic boundary phase, the boundary phase acts as a pinning center, but when the grain-boundary phase has a comparatively low Curie temperature, the high-temperature magnetism of the system is that of a weakly interacting ensemble of magnetic particles. In spite of some residual paramagnetic exchange coupling, which is discussed in this work, this mechanism enhances the coercivity.",
author = "Sellmyer, {David J.} and J. Zhou and H. Tang and R. Skomski",
year = "2001",
month = "12",
day = "1",
language = "English (US)",
volume = "674",
pages = "U5.8.1--U5.8.12",
journal = "Materials Research Society Symposium - Proceedings",
issn = "0272-9172",
publisher = "Materials Research Society",

}

TY - JOUR

T1 - Hybrid high-temperature nanostructured magnets

AU - Sellmyer, David J.

AU - Zhou, J.

AU - Tang, H.

AU - Skomski, R.

PY - 2001/12/1

Y1 - 2001/12/1

N2 - The hysteretic behavior of two-phase permanent magnets for high-temperature applications is examined. A variety of systems have been synthesized and investigated, including Sm-Co-Cu-Ti bulk magnets, SmCo5:Cu-Ti thin-film materials, and mechanically milled Sm-Co-Zr magnets. The hybrid character of the material leads to very high room-temperature coercivities, between 30.2 and 43.6 kOe, and to the survival of a comparatively large part of the coercivity at high temperatures (12.3 kOe at 500°C for SmCo6.5Cu0.8Ti0.3). The coercivity reflects the structure and chemical composition of the material. When ferromagnetic grains are separated by a ferromagnetic boundary phase, the boundary phase acts as a pinning center, but when the grain-boundary phase has a comparatively low Curie temperature, the high-temperature magnetism of the system is that of a weakly interacting ensemble of magnetic particles. In spite of some residual paramagnetic exchange coupling, which is discussed in this work, this mechanism enhances the coercivity.

AB - The hysteretic behavior of two-phase permanent magnets for high-temperature applications is examined. A variety of systems have been synthesized and investigated, including Sm-Co-Cu-Ti bulk magnets, SmCo5:Cu-Ti thin-film materials, and mechanically milled Sm-Co-Zr magnets. The hybrid character of the material leads to very high room-temperature coercivities, between 30.2 and 43.6 kOe, and to the survival of a comparatively large part of the coercivity at high temperatures (12.3 kOe at 500°C for SmCo6.5Cu0.8Ti0.3). The coercivity reflects the structure and chemical composition of the material. When ferromagnetic grains are separated by a ferromagnetic boundary phase, the boundary phase acts as a pinning center, but when the grain-boundary phase has a comparatively low Curie temperature, the high-temperature magnetism of the system is that of a weakly interacting ensemble of magnetic particles. In spite of some residual paramagnetic exchange coupling, which is discussed in this work, this mechanism enhances the coercivity.

UR - http://www.scopus.com/inward/record.url?scp=0035559983&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035559983&partnerID=8YFLogxK

M3 - Conference article

AN - SCOPUS:0035559983

VL - 674

SP - U5.8.1-U5.8.12

JO - Materials Research Society Symposium - Proceedings

JF - Materials Research Society Symposium - Proceedings

SN - 0272-9172

ER -