Abstract The electromagnetic properties of YBa2Cu3O7-δ (Y-123) were improved by reducing size of the secondary phase Y2BaCuO5 (Y-211) via ultra-sonication and optimization of the top seeded melt growth (TSMG). Ultra-sonication a clean and low-cost technique, which excels over other techniques in producing refined Y-211 particles with sharp edges, uniform size, and contamination-free surfaces. The Y-211 powder was ultra-sonicated for various intervals ranging from 0 to 100 min, with a constant power (300 W) and frequency (20 kHz). Single grain Y-123 bulks were prepared from these powders and their electromagnetic and superconducting performance was compared. The superconducting transition temperature of all the bulk samples was around 91 K and the transition width was less than 1.5 K. At 77 K, the highest critical current density (Jc) and trapped field was found in the sample with Y-211 ultra-sonicated for 100 min. Flux pinning studies revealed a strong contribution from δTc pinning. The present results demonstrate that the superconducting performance can be improved by ultra-sonication process producing nanometer-sized Y- 211 particles in bulk Y-123. This technique can help to produce large bulk superconductors for commercial exploitation.

中文翻译：

---

通过超声波精制 Y2BaCuO5 不含 PtO2 和 CeO2 提高熔体生长块状 YBa2Cu3Oy 的超导性能

摘要 YBa2Cu3O7-δ (Y-123) 的电磁性能通过超声处理和顶部引晶熔体生长 (TSMG) 的优化来减小第二相 Y2BaCuO5 (Y-211) 的尺寸。超声波是一种清洁且成本低的技术，在生产具有锋利边缘、均匀尺寸和无污染表面的精细 Y-211 颗粒方面优于其他技术。Y-211 粉末以恒定功率 (300 W) 和频率 (20 kHz) 超声处理从 0 到 100 分钟的各种时间间隔。用这些粉末制备单颗粒 Y-123 块体，并比较它们的电磁和超导性能。所有大块样品的超导转变温度约为 91 K，转变宽度小于 1.5 K。在 77 K 时，在 Y-211 超声处理 100 分钟的样品中发现了最高的临界电流密度 (Jc) 和俘获场。通量钉扎研究揭示了 δTc 钉扎的强大贡献。目前的结果表明超导性能可以通过超声处理在块状 Y-123 中产生纳米尺寸的 Y-211 颗粒来提高。该技术有助于生产用于商业开发的大型超导体。