FINE GRAIN DENSE FERRITES
Abstract
A number of new compositions were prepared in the vicinity of the compensation point in the series Ni sub 1-xCoxFe2O4. No systematic variation in the threshold field or magnetic loss was observed with cobalt concentration, although threshold fields were as high as 108 Oe at KU-band. Lowering the hot- pressing temperature from 1200 to 1150 C had no consistent effect on microwave properties. Annealing studies at 1200 and 1250 C indicate that the threshold field decreases significantly with time for nickel and nickelmanganese ferrites, whereas it remains high in nickel-cobalt ferrites. The magnetic loss in general decreases with increasing time; it decreases most for nickel and nickel- manganese ferrites, and least for nickel-cobalt ferrites. A satisfactory device geometry has been established for a differential phase-shift circulator. Low power phase shift and insertion loss measurements have been made on a conventional and finegrain, nickel-cobalt ferrite. Although the insertion loss of the fine-grain ferrite is about double that of the conventional material due to a magnetic loss of approximately twice that of the conventional material, a circulator with less than or equal to 0.5 dB loss can be constructed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 1965
- Accession Number
- AD0464540
Entities
People
- A. E. Booth
- A. E. Paladino
- J. J. Green
- J. Q. Owen
- J. S. Waugh
Organizations
- RTX