A Superconducting Sub-Structure in Sintered YBaCu3O7-x Plates

Abstract
We have measured magnetization of sintered YBa2Cu3O7-x plates in a parallel magnetic field at 77 K. It was found that the difference ΔM in the magnetization between increasing and decreasing processes of the external field depends little upon the thickness of the plate, and it is predicted by the `critical-state' model that the difference is proportional to the thickness in a uniform specimen. The present experimental results suggest that the sintered plates consist of small superconducting sub-structures and that the superconducting connections among these sub-structures are not strong.