Ferrites for Microwave Circuits and Digital Computers

Abstract

Ferrites of the system MgO–MnO–Fe2O3 have been investigated, and two new classes of magnetic materials have been developed. One class of ferrite has low losses and shows the Faraday rotation effect at microwave frequencies, which makes it useful in new types of microwave components. A second class of ferrite has a rectangular hysteresis loop and inherent high resistivity which allows digital computer magnetic memories to be operated at much greater speeds than was possible with the familiar magnetic metal alloys. Both classes of ferrites are now commercially available.