Dissociation of grain boundary dislocations in YBa₂Cu₃O_7-δ-coated conductors

The study reports the discovery of a new structure and spacing versus angle relation for a prevalent type of small-angle grain boundary in YBa₂Cu₃O_7-δ (YBCO)-coated conductor films. Small-angle [001] tilt grain boundaries with (110) planes exhibit partial grain boundary dislocations (GBDs) separated by stacking faults. The dissociated grain boundary structures have twice the number of GBDs and shorter interdislocation core channel widths than Frank's geometrical rule predicts. This will require a significant alteration of models of supercurrent flow through arrays of small-angle grain boundaries in YBCO coated conductors. A thorough analysis of the stacking fault energy has been conducted based on the basis of anisotropic elasticity.