The Effect of the Pre-Infiltration Temperature on the Liquid-Phase Infiltration Characteristics and the Magnetic Properties of Single-Domain GdBCO Bulk Superconductors

In this study, the effect of the pre-infiltration temperature (Ti) on the liquid-phase infiltration characteristics and its effect on the magnetic properties of single-domain GdBCO bulks prepared by the top-seeded infiltration growth (TSIG) method are comprehensively investigated. The results reveal that (1) the liquid Ba-Cu-O phase (LP) did not uniformly infiltrate into the Gd2BaCuO5 (Gd-211) solid-phase pellet (SPP). (2) The initial melting and infiltration of the LP occurred at approximately 920 °C. The average infiltration depth and amount of LP that infiltrated the SPP increased with increasing Ti accompanied by the shrinkage and depletion of the LP pellet. (3) The LP penetrated up to the top surface of the SPP and uniformly infiltrated throughout the SPP when the Ti was approximately 960 °C and 1020 °C, respectively. (4) The mean Gd-211 particle size of the pre-infiltrated SPP increased from 1.94 µm at 920 °C to 2.52 µm at 1040 °C as the Ti rose. (5) The magnetic properties and microstructure of the single-domain GdBCO bulks were significantly influenced by the microstructure of the pre-infiltrated SPP. The largest levitation force of 35.64 N and trapped field of 0.23 T were obtained in the single-domain GdBCO bulks at an infiltration Ti of 960 °C.