Rugged low-resistance contacts to YBa2Cu3O<i>x</i>

Abstract

We have made rugged low-resistance contacts to the high Tc superconductor YBa2Cu3Ox by melting gold beads onto the surface of the material. After retreating the samples in oxygen, we have measured contact resistance &amp;lt;50 μΩ. This allowed a direct current of ≊5 A to pass through the contacts without heating while the sample remained in the superconducting state at 20 K. In this letter we present results of scanning electron microscopy, and measurements of contact resistance, critical current, and shear strength on these contacts. Such contacts will be of practical use in high current carrying applications of the new high Tc superconductors.