Magnetic domain structures of overquenched Nd-Fe-B permanent magnets studied by electron holography

Y. G. Park, D. Shindo

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

Microstructures and magnetic domain structures of overquenched Nd-Fe-B permanent magnets have been investigated in detail by transmission electron microscopy. While magnetic domain boundaries are clarified by Lorentz microscopy, magnetization distribution in the domains is clearly observed by electron holography. In the as-quenched magnet, the size of the magnetic domains is in the range from 200 to 500nm and the direction of the magnetic lines of force changes gradually in wide region, while in the annealed one having the crystalline phase of Nd2Fe14B, the direction of the magnetic lines of force changes drastically especially at the grain boundaries. Furthermore, the direction of the magnetic lines of force changes more drastically in the specimen annealed at 893K than the specimen annealed at 843K. This result clearly indicates that the magnetocrystalline anisotropy is enhanced with the increase of annealing temperature, resulting in strong domain wall pinning.

Original languageEnglish
Pages (from-to)68-74
Number of pages7
JournalJournal of Magnetism and Magnetic Materials
Volume238
Issue number1
DOIs
Publication statusPublished - 2002 Jan 1

Keywords

  • Domain wall pinning
  • Electron holography
  • Magnetic flux density
  • Magnetization distribution
  • Reconstructed phase image

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Magnetic domain structures of overquenched Nd-Fe-B permanent magnets studied by electron holography'. Together they form a unique fingerprint.

Cite this