Superconducting critical current density (J c) at 4.2 K for superconducting Sr2VFeAsO3-δ tape fabricated by powder-in-tube process was enhanced up to 285 A cm-2. Cross-sectional SEM images for superconducting Sr2VFeAsO3-δ wire/tapes indicated that void fraction f void was reduced from 12.8% for the round wire to ∼2.5% for the tapes. The decrease in f void suppresses the so-called "weak-links" and therefore enhances the J c. In order to enhance J c, the annealing condition should be optimized. The optimal annealing condition enforces the link between grains and avoids the loss of oxygen atoms in the superconducting core.
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