Improvement of spatial homogeneity in GdBCO/IBAD-MgO coated conductor

Recent process optimization allows improving homogeneity and a significant increase of J_c in GdBa₂Cu₃O_7-δ deposited on ion-beam assisted deposited MgO template (GdBCO/IBAD-MgO). We applied low-temperature laser scanning microscopy and laser scanning thermo-electric microscopy (LSTEM) to investigate local dissipation and defects simultaneously in recent GdBCO/IBAD-MgO coated conductor. By using high-resolution LSTEM, we could detect current blocking obstacles which are responsible for the large scale local dissipation. Data on the present GdBCO/IBAD-MgO coated conductors point out a significant reduction of current blocking obstacles compared to the previous process. We have shown the improvement of spatial homogeneity in the recent GdBCO/IBAD-MgO coated conductors. Current blocking obstacles are much less densely distributed as compared to previous YBCO/IBAD-GZO coated conductor. Obstacles larger than several micrometer significantly increase local dissipation whereas smaller defects do not influence it noticeably. 2D map of the phase delay component of the thermoelectric voltage lock-in signal is effective to analyze current blocking obstacles having action upon local dissipation.