Development of a 100-m-long Eu₁Ba₂Cu₃O_7-δ + BaHfO₃-coated Conductor with High In-field Property using the IBAD/PLD Method

Abstract

The introduction of artificial pinning centers such as BaZrO₃ (BZO), BaSnO₃ (BSO) and BaHfO₃ (BHO) nano-rods into REBCO film is effective to improve in-field critical currents (I_c). In particular, BHO doping into Gd₁Ba₂Cu₃O_7-δ (GdBCO) has been found to exhibit high in-field I_c values under a wide range of temperatures and magnetic fields. However, the increase of I_c values of the GdBCO + BHO system exhibited somewhat of a saturated manner, with thickening of the superconducting films to more than 3μm. In this work, a new combination of Eu₁Ba₂Cu₃O_7-δ (EuBCO) + BHO system was investigated using the IBAD/PLD process to improve in-field performance in thick films. As a result, it was found that a EuBCO + BHO thick film showed an extremely high I_{c, min} property of 141 A/cm-w at 77 K and 3 T. A 93.7-m-long EuBCO + BHO CC estimated I_c value of 108 A/cm-w at 77 K and 3 T was successfully fabricated.