LINEWIDTH OF NONORIENTED POLYCRYSTALLINE HEXAGONAL FERRITES WITH LARGE MAGNETIC ANISOTROPY FIELDS
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1963
- Accession Number
- AD0416329
Entities
People
- Gilbert Mccall
- Isidore Bady
Organizations
- United States Army Communications-Electronics Command