GRAIN SIZE EFFECTS ON SWITCHING PROPERTIES OF LITHIUM FERRITES.

Abstract

The study was made to determine the effects of grain size on the switching properties of lithium ferrite. Lithium ferrite (Li.5Fe2.5O4) powders were prepared by five different techniques which were freeze drying, flame spraying, standard commercial processing, fluid-bed reaction, and reaction of Li2CO3+Fe2O3 mixture. These powders were densified by hot pressing or conventional sintering. Except for the freeze-dried powder, their magnetic properties were similar for a given grain size, but their densification and grain growth characteristics varied greatly. The magnetic properties evaluated as a function of grain size were coercive force, switching speed, switching constant, squareness, and temperature stability. These properties were evaluated over a 0.7 to 16.0 micron grain size range and the effects of grain size on switching speed and coercive force were established. It is shown that samples with a 5.0 micron grain size have more than a two times faster switching speed with little or no increase in coercive force, when compared with 16.0 micron grain size samples. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1969
Accession Number
AD0688881

Entities

People

  • A. Dunlap
  • G. Sands
  • R. W. Babbitt

Organizations

  • United States Army Communications-Electronics Command

Tags

DTIC Thesaurus Topics

  • Coercivity
  • Flame Spraying
  • Freeze Drying
  • Grain Growth
  • Grain Size
  • Hot Pressing
  • Magnetic Properties
  • Sintering
  • Switching
  • Thermal Spraying

Fields of Study

  • Materials science

Readers

  • Combustion science or combustion engineering.
  • Materials Science and Engineering.
  • Surface Coatings Technology.