GB1367130A - Magnetic bubble domain system - Google Patents

Abstract

1367130 Moving domain devices ROCKWELL INTERNATIONAL CORP 22 Feb 1972 [12 March 1971 (2)] 8175/72 Heading H3B In a bubble domain system domains are propagated along strips of material 12, Fig. 1, having restricted portions such as 14, 15. Because the edges of the strip tend to repel domains this provides preferred sites in the unrestricted portions, and the pattern of propagation conductors may be simplified. One possible propagation conductor is shown at 30 in Fig. 1, and it passes over the strip a little to the right of the centres of the restricted portions; the direction of the off-centre displacement determines which way the domains move along the strip when A.C. is passed through the conductor. Another conductor is shown in Fig. 2 and takes the form of a sheet overlying the strip and having windows over the right hand parts of the unrestricted portions. When A.C. is passed through this sheet the associated field again moves the domains. The strip may be formed by etching away part of a film on a substrate as shown, or by filling grooves in a substrate with bubble domain material as in Specification 1,367,123 or by etching grooves partly through a bubble domain film on a substrate as in Specification 1,367,128. Materials.-The substrate is preferably a monocrystalline garnet of J 3 Q 5 O 12 formula, such as Y 0À45 Gd 2À55 Ga 5 O 12 , or Dy 0À65 Gd 2À35 Ga 5 O 12 or Sm 3 Ga 5 O 12 . The strip material is also preferably a single crystal garnet of J 3 Q 5 O 12 formula, such as Y 3 Ga 1À2 Fe 3À8 O 12 or Tb 3 Fe 5 O 12 . The substrate may use a non-garnet oxide, particularly if the strip is an orthoferrite.