Magnetic devices by selective reduction of oxides
AssigneeBell Telephone Laboratories, Incorporated
InventorsMurray Robbins, Richard C. Sherwood
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Abstract
Magnetic material is made by reducing an oxide powder compact having at least one nonreducible oxide species. A typical mixture of nickel, iron, and aluminum oxides selectively reduces to form a material having a typical permeability of 10 or more and high resistivity. Reduced eddy current losses occur in devices made from such material.
Claims8
A method of making a magnetic material by steps comprising compacting oxide powder comprising at least one oxide species of a magnetic metal, thereby forming an oxide compact, and heating said compact in a reducing environment, thereby reducing said one oxide species to a metal,
- characterized in that said oxide powder further comprises at least one oxide species which does not substantially reduce during said heating, and which oxide species substantially migrates to grain boundaries of said magnetic metal or alloys thereof during said reducing step, thereby rendering the magnetic material obtained after said reducing step substantially insulated so that the macroscopic resistivity of said magnetic material is at least 1.0 ohm-centimeters.
Dependencies are inferred from the claim text.