PERMANENT MAGNET MATERIALS

Abstract

An experimental comparison was made of the particle sizes of single domain ferromagnetic powders by means of methods based on the electron microscope, the broadening of x-ray diffraction lines, and the measurement of surface areas with nitrogen adsorption. The powders studied included 5-u particle size GAF (General Aniline and Film Corp) 'HP', 2-micron GAF 'p-818', 600-A Fe-8, 400-A Fe-7, 400-A Hyflux, 250-A NOL-1, 200-A NOL-2, and 200-A Ugine. Reasonably good agreement was obtained between the x-ray diffraction method and the electron microscope method. However, the nitrogen adsorption sizes were always higher. The results indicated that the electron microscope can be used to determine reliable particle size distributions of metallic single-domain powders provided that sufficient care is taken to produce good dispersions. In the case of single-domain ferromagnetic particles, the dispersions may be obtained by magnetic means. The electron microscope distributions must be compared to the average sizes obtained from 1 or 2 independent methods.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 31, 1952
Accession Number
AD0021995

Entities

People

  • Alan D. Franklin

Organizations

  • Franklin Institute

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Adsorption
  • Bragg Angle
  • Coefficients
  • Diffraction
  • Electron Microscopes
  • Equations
  • Heat Energy
  • Ideal Gas Law
  • Magnetic Fields
  • Magnetic Properties
  • Materials
  • Measurement
  • Military Research
  • Particle Size
  • Thermodynamics
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Physics

Readers

  • Regression Analysis.
  • Superconducting Magnet Technology
  • Thin Film Deposition Science.

Technology Areas

  • Microelectronics