Effect of low temperature annealing on doping level and superconducting properties for IBAD/PLD-YBCO coated conductor

The effect of low temperature annealing on the superconducting properties of PLD-YBCO tape has been investigated with varying atmosphere. The Tc of the as-prepared sample is 88.5 K, for the sample post-annealed at 200 °C in Ar atmosphere showed 91.5 K, indicating Tc is sensitive to low temperature annealing. In spite of the higher Tc the Jc and μ0Hirr for the Ar-annealed sample were lower than those for the as-prepared sample. This indicates that the as-prepared PLD-YBCO tape is in the carrier overdoped state. It was found that re-annealing in which the sample was slowly cooled from 450 °C in pure oxygen atmosphere could restore the Jc-degradation, demonstrating that oxygen absorption-release occurred reversely.