High performance superconducting joint for MgB2 films

Abstract

Large-area high-quality MgB2 thin films were needed in many superconducting applications such as superconducting radio frequency (RF) cavities. However, fabricating large films with high quality can be difficult. Thus, a jointing method between MgB2 films can be crucial in a lot of superconducting electronic applications. In this article, we successfully fabricated superconducting joints for MgB2 films. The sol-gel of Mg(BH4)2·Et2O was used as the glue. Two types of MgB2 joints were shown in this work, a two-piece face-to-face joint, and a three-piece bridging joint. The sol-gel derived MgB2 joints have shown very good superconducting performance, with a high superconducting critical temperature (TC) of 40 K, a high critical current (IC) of 340 mA at 0 T, and very nice current capacity in magnetic fields up to 4 T.