Using radiation damage to increase critical currents in high temperature superconductors

Abstract

The vast potential for technological applications of high temperature superconductors can not yet be exploited because 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 defects into the material which can pin the vortices, thereby 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 YBa2Cu3O7. The geometry and pinning strength of the defects varies greatly with the type of irradiation.