The development of rare earth (RE) Ba2Cu3Oy (REBCO) coated conductors has been carried out by many groups. The critical current density (Jc) in high magnetic fields needs to be improved for superconducting applications. We have fabricated BaHfO3 (BHO)-doped SmBa2Cu3Oy films on ion beam-assisted deposition (IBAD)-MgO substrates using pulsed laser deposition (PLD). In this study, we introduce a seed layer technique. As a result, the appropriate growth temperature (Ts) is expanded to higher temperature range without BaCeO3 outgrowth around the interface of the SmBCO and CeO2 cap-layer. We were able to control the configurations of the BHO nanorods within the SmBCO films as compared to the conventional PLD method. The SmBCO + BHO (1.4 vol.%) films, which were fabricated at a Tsupper of 900ºC, showed that the Jc in the magnetic field (B // c) was improved as compared to pure-SmBCO films. Furthermore, the global pinning force density reached 21 GN/m-3 at 77 K in B = 2 T.
Recently, high-temperature, superconducting coated conductors (CCs) are being used for various applications, and further improvement of the in-field transport property is required. In order to improve the magnetic field and angular dependences, introducing artificial pinning centers (APC) into the superconducting layer is known to be effective. Moreover, it is necessary to fabricate long CCs while maintaining excellent properties in order to reduce manufacturing costs. We succeeded in achieving the above-mentioned issues by using trifluoloacetate solution metal organic deposition (TFA-MOD), and fabricated a long Y0.77Gd0.23Ba2Cu3Oy (YGdBCO) + BaZrO3 (BZO) CC using batch furnace heat treatment. We also confirmed the superior infield performance of this CC through transport measurements.