Microstructures and critical currents in high-T_c superconductors

摘要

Microstructural defects are the primary determining factors for the values of critical-current densities in a high T_c superconductor after the electronic anisotropy along the a-b plane and the c-direction. A eview is made to assess firstly what would be the maximum achievable critical-current density in YBa_2 Cu_3 O_u if nearly ideal pinning sites were introduced and secondly what types of pinning defects are currently introduced or exist in YBa_2Cu_3O_u and how effective are these in pinning vortices.