Development of long GdBCO coated conductor using the IBAD/MPMT-PLD method

We have developed long GdBa 2 Cu 3 O 7− X (GdBCO) coated conductors by a multi-plume and multi-turn pulsed laser deposition (MPMT-PLD) method and have successfully fabricated 32 and 60.7 m long GdBCO coated conductors with a high critical current, I c , and high deposition rate. The I c of the 32 and 60.7 m long GdBCO coated conductors were 205 A ( J c = 1.36 MA cm −2 ) and 183 A ( J c = 1.45 MA cm −2 ), respectively, at 77 K and 0 T. In addition, they exhibited higher I c values in a magnetic field than a YBa 2 Cu 3 O 7− X (YBCO) coated conductor: typically 20 A at 77 K and 3 T while the value for a YBCO coated conductor is 8 A. These high I c values are due to the smaller number of a -axis oriented grains in GdBCO than in YBCO. Furthermore, the speed of production of the GdBCO layer was increased to 10 m h −1 while that of the former YBCO coated conductor was 3.75 m h −1 . The material yield of long GdBCO layers using the MPMT-PLD method was about 26–28%. The high I c of GdBCO in a magnetic field, the high production rate and the high material yield are promising for applications.