Methods are described for the ceramic fabrication of ferrite toroids of up to eight inches length, and ferrite substrates of four square inch area. These parts exhibit intrinsic technical properties and as-fired mechanical tolerances suitable for the construction of certain latching ferrite microwave phasers and microstrip ferrimagnetic devices. Further, the minimization of machining to obtain useable mechanical tolerances for ferrite devices of the latching and microstrip classes provides for a substantial cost reduction of the ferrite parts. A pressing method was developed which yields an eight inch toroid of uniform green density. Firing methods were developed which result in close control of mechanical tolerances of both substrates and toroids. The beneficial effects of using manganese to reduce magnetostriction and improve remanent flux density are discussed. Employment of high dielectric constant 20 inserts in the ferrite toroids to increase microwave phase shift and reduce the size of the ferrite toroid are described. Finally, measurement techniques for economic quality control procedures relative to mass production of toroids are suggested. Author
Final technical rept. 15 Nov 67-15 Jul 71,
Prepared in cooperation with Trans-Tech, Inc., Rockville, Md.