Using radiation damage to increase critical currents in high temperature superconductors

摘要

The vast potential for technological applications of high temperature superconductors can not yet be exploted because of their low critical current densities. The critical current densities in these materials at high temperatures and in high magnetic fields are largely limited by the motion of magnetic flux vortices. This motion can be inhibited through the introduction of defects into the material which can pin the vortices, therebly eliminating the electrical resistance. Radiation damage has proven to be an effective means of introducing such defects. We present the results of a study on the effects of both proton and heavy ion irradiation on single crystals of the high temperature superconductor YBa_2Cu_3O_7. The geometry and pinning strength of the defects varies greatly with the type of irradiation.