Hopgood, Calimafde, Kalil, Blaustein & Judlowe
Method for producing a magnetic bias field
 The invention provides a method for producing a magnetic bias field in a magnetic bubble domain memory device. The method comprises coupling a magnetic bubble domain element with a permanent magnet. The permanent magnet is formed of a rare earth metal-containing alloy for use in the bubble domain memory device in respect of the reversible temperature coefficient of the magnet capable of being in compliance with the temperature coefficient of the bubble disappearance field of the memory device. The alloy characteristically contains nickel as an essential component so that the composition of the alloy is expressed by the formula EQU R(Co.sub.1-x-y Cu.sub.x Ni.sub.y).sub.z, in which R is a rare earth element, e.g. samarium or cerium, and s, y and z are each a positive number from 0.001 to 0.4, from 0.001 to 0.6 and from 4.0 to 9.0, respectively, with the proviso that x+y is smaller than 1. 
Shin-Etsu Chemical Co., Ltd.
C H H
C22C H01F H01F
inventional inventional inventional
Ken Hideaki Yoshio
Ohashi Kikuchi Tawara