Weak link properties in polycrystalline high-T_c superconductors

摘要

It is well known that the weak link behavior of grain boundaries in high transition temperature (T_c) superconductors results in a lower critical current density (J_c) in polycrystalline samples compared with the J_c carried within individual grains. In this lecture, is reviewed the strategy for increasing J_c of polycrystalline superconductors based on studies on an anisotropy in J_c of single crystals and studies on the weak link behavior by using bicrystals. Then, experimental examples for increasing J_c of polycrystalline superconductors are presented.