Abstract
Dislocations accompanied by stacking faults are found in intragrain regions of polycrystalline YBa2Cu3O7-δ which is prepared by a solid-state reaction process. The process is characterized by the inclusion of high-temperature sintering. Transport critical current density Jc is measured in a liquid nitrogen bath at magnetic fields H up to 1.5 T. Jc at H>0.3 T hardly deteriorates, producing a nearly flat Jc-H characteristic at high fields. The result shows that the dislocations probably act as pinning centers for magnetic flux.