Efficient integration of Gd-2411-W artificial pinning in single-direction melt-grown GdBCO/Ag bulks in high amounts

To increase the application potential of superconducting materials, their key properties, such as critical current density, trapped field, and overall homogeneity, must be improved. It is long established that these properties can be enhanced by pinning phase addition. However, the innate fragility of top-seeded melt growth has prohibited a substantial amount of pinning from being added to bulks grown by top-seeded melt growth. Due to its robustness, the newly developed single-direction melt growth (SDMG) method should allow the integration of significantly higher mass concentrations into the superconducting matrix. For the GdBCO/Ag system, the Gd-2411-W (Gd₂Ba₄Cu_2‒xW_xO_12‒ẟ) pinning phase was selected and integrated into the superconducting matrix in 0%, 1%, 2%, 3%, 5%, 7.5%, 10%, and 13% mass concentration. While such a high concentration of pinning would negatively impact superconducting properties, it is astonishing that it did not significantly impede crystal growth. In the sample containing 3 wt.% pinning phase, a significant increase in the maximum trapped field (over 35%) was observed compared to the reference without a pinning phase. In addition, high trapped field homogeneity typical for SDMG-grown bulks was observed in all prepared samples. The obtained results show the extreme robustness of the SDMG growth and hint at enormous potential for SDMG-grown bulks containing high amounts of artificial pinning.