Effect of Silver Substitution Threshold on the Superconducting Properties of IG Processed Bulk YBCO/Ag Composite Superconductors

In this article, we report anomalous substitution of Ag in Cu sites in Y-123 lattice during the fabrication of bulk YBCO/Ag composites via the Infiltration Growth Processing technique. We have observed concentration quenching of Ag in the Y-123 unit cell which implies a threshold for Ag substitution in Cu sites. We find gradual variation in properties with increase in Ag content up to a threshold value beyond which the superconducting properties are altered significantly. We discuss the effect of substitution threshold of Ag on the magnetic and superconducting properties of these composites and the optimum substitution level of Ag for enhanced properties