Influence of nanoparticles on flux pinning properties in TFA-MOD processed YGdBCO coated conductor

The flux pinning properties in a magnetic field of various directions are investigated for trifluoroacetates-metal organic deposition (TFA-MOD) processed Y1-xGdxBa2Cu3Oy (YGdBCO)-coated conductors with the superconducting layer of 0.5 μm thick with artificial BaZrO3 (BZO)-nanoparticles. It is found that the critical current density is enhanced in a wide range of field angle except around the direction parallel to the a - b plane, resulting in low field-angle anistropy. The enhancement of Jc in the wide range of field angle is attributed to the isotropic pinning of nanoparticles. The decrease in the critical current density in the field direction parallel to the a - b plane is considered to be caused by limitation of growth of stacking faults by distributed BZO nanoparticles. The observed results were theoretically explained by the flux creep-flow model and the above speculation of the pinning mechanism was confirmed.