Magnetic devices including amorphous alloys

Abstract

The disclosed magnetic devices, including a magnetically coupled conducting path, incorporate amorphous, low magnetostriction alloys of the general formula (Co.sub.a Fe.sub.b T.sub.c).sub.i X.sub.j, the 'metallic' constituents thereof being within the parenthetical expression. T, in the formulation, is selected from among Ni, Cr, Mn, V, Ti, Mo, W, Nb, Zr, Pd, Pt, Cu, Ag and Au, X being at least one 'glass former' selected from among P, Si, B, C, As, Ge, Al, Ga, In, Sb, Bi and Sn. The 'metallic' constituents comprise from 70-90 atomic percent of the alloy with cobalt being present in an amount of at least 70 atomic percent of the 'metallic' constituents. The described material has been prepared by rapid cooling from the liquid, directly to the shape needed for fabrication of the device (e.g., tape to be wound to form an inductor core). When the amorphous material is heat treated for from 30 minutes to two hours at temperatures from 125 degrees Centigrade to 200 degrees Centigrade, it exhibits a temperature stabilized magnetic permeability. The fabrication of such devices as temperature stabilized inductors and transformers is contemplated.