Development of REBCO Coated Conductors by TFA-MOD Method With High Characteristic in Magnetic Field

Y_xGd_{(1 - x)}Ba₂Cu₃ O_y coated conductors (CCs) with artificial pinning centers (APCs) were fabricated by the trifluoroacetates-metal organic deposition method using a batch heat-treatment process. This process has been industrially applied to fabricate long superconducting tapes that have high critical current (I_c). From the viewpoint of applications, the characteristics in magnetic fields become further important, and one solution has been shown previously as introduction of APCs such as BaZrO₃. We applied the technique to our CCs fabrication process. The heat-treatment conditions, specifically total gas pressure, oxygen concentration, and crystallization temperature, were optimized for the batch heat-treatment process. As a consequence, fabricated CC showed extremely high characteristic Jc value of 3.5 MA/cm² in self field, and 0.3 MA/cm² at 3 T in liquid N₂. Moreover, by cross-sectional transmission electron microscopy observation, it was confirmed that the APC was distributed uniformly. Furthermore, the anisotropy of the pinning center is also examined based on the evaluation result of the angular dependence of Jc in 3T.