DISLOCATION DISSOCIATION ON CLIMB PLANE IN TEXTURED YBa₂Cu₃O_7-\delta SUPERCONDUCTOR

Using high resolution electron microscopy, the structure of 100 tilt boundary with misorientation of 1.2° in YBa₂Cu₃O_7-\deltahas been determined. The boundary is shown to consist of an array of partial dis-locations, These partials result from the dissociation of a perfect dislocation with a Burgers vector 0, 0, c on its climb plane according to the reaction, b→b₁+b₂+b₁+b₂+b₁+b₂. Here b=00c, b₁=O,b/2, c/6 (or a/2, 0, c/6 ). b₂=0, -b/2. c/6 (or -a/2, 0, c/6 ). The spacing between the perfect dislocations satisfies the Read-Shockley formula. There exist no amorphous phases in the boundary region.