Accession Number:

AD0416329

Title:

LINEWIDTH OF NONORIENTED POLYCRYSTALLINE HEXAGONAL FERRITES WITH LARGE MAGNETIC ANISOTROPY FIELDS

Descriptive Note:

Corporate Author:

ARMY ELECTRONICS LABS FORT MONMOUTH NJ

Personal Author(s):

Report Date:

1963-03-01

Pagination or Media Count:

31.0

Abstract:

Theoretical calculations are made of the linewidth of nonoriented, polycrystalline, hexagonal ferrites with large magnetic anisotropy fields, including both uniaxial and planar ferrites. The nonoriented ferrites are considered to be composed of crystallites whose C axes are radomly oriented over all possible solid angles. For a given biasing field, the solid angle omega is calculated within which the C axis of a crystallite must lie in order that its resonant frequency will differ from the test frequency by a chosen amount. All crystallites within this angle are presumed to absorb energy equally all other crystallites are presemed not to absorb any energy. The loss term of susceptibility is proportional to omega, and a linewidth can be calculated. It is shown that the linewidth of a nonoriented uniaxial ferrite is considerably wider than the linewidth of a nonoriented planar ferrite. Since imperfect orientation is a major contributor to the linewidth of oriented hexagonal ferrites, it is seen that imperfect orientation will affect the linewidth of uniaxial ferrites far more than that of planar ferrites. This is supported by test data which show that nonoriented planar ferrites can have a linewidth considerably narrower than the narrowest linewidth obtained with oriented uniaxial ferrites.

Subject Categories:

  • Properties of Metals and Alloys
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE