Positron Annihilation Studies of Very Fine Structured Materials.

Abstract

UAn Fe-Nd-B permanent magnet alloy (Crumax 30) has been evaluated as a function of thermal treatment by means of positron annihilation lifetime spectroscopy. The results of this preliminary study indicate that the room temperature lifetime spectra can be accurately modeled using either a two-component or a partially constrained three-component fit. The thermally-induced variations in lifetime spectra can be correlated with the concomitant decrease in magnetic coercivity in a manner that is consistent with thermally-induced microstructural transformations reported in the literature. The demonstrated sensitivity of positron annihilation lifetime spectroscopy to thermally-induced changes in both microstructure and magnetic coercivity suggests that a more thorough systematic positron annihilation evaluation of Fe-R-B alloys could provide further insight into the relationship between processing, structure and magnetic properties.

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Document Details

Document Type
Technical Report
Publication Date
Dec 17, 1985
Accession Number
ADA163822

Entities

People

  • Phillip L. Jones

Organizations

  • Duke University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Coercivity
  • Electron Density
  • Electrons
  • High Temperature
  • Low Temperature
  • Magnetic Fields
  • Magnetic Materials
  • Magnetic Properties
  • Materials
  • Materials Processing
  • Materials Science
  • Military Research
  • Permanent Magnets
  • Positrons
  • Security
  • Standards
  • Universities

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Solar Physics
  • Superconducting Magnet Technology