Zhang Yufeng, Lou Ziwei, Zhang Penghe, Li Chunyan, Zhang Jiaying, Zhang Xiaojuan
College of Mathematics and Physics, Shanghai University of Electric Power, 1851 Hucheng Ring Road, New Pudong District, Shanghai 201306, China.
Micromachines (Basel). 2022 Apr 29;13(5):701. doi: 10.3390/mi13050701.
The performance of critical current density of GdBaCuO (GdBCO or Gd123) superconductor bulk has an important influence on its practical applications. In this work, four single-domain GdBCO superconductor bulks were successfully processed by the modified top-seeded melt-texture growth method. The addition of a YBaCuO (Y123) liquid source with different thicknesses, 0 mm (S0), 3 mm (S3), 5 mm (S5), 7 mm (S7), was introduced to study the influence on the superconducting properties. GdBCO bulk with the addition of the Y123 liquid source with a 3-mm thickness shows the best superconducting properties. The addition of the Y123 liquid source results in a decrease in the Gd ion concentration required for Gd123 growth; thus, GdBaCuO (Gd211) particles in the liquid source need a larger self-decomposition to diffuse Gd ions to Gd123 growth front, which refines the size and leads to a homogenous distribution of the Gd211 particles in the bulks. Thus, the more pinning centers of fined Gd211 particles improve the superconducting properties of GdBCO bulk. With increases in the thickness of Y123 liquid source to 5 mm and 7 mm, high RE (Gd and Y) concentration can coarsen Gd211 particles and fuse with Gd211 liquid source. The superconducting properties apparently drop. Therefore, the addition of a Y123 liquid source with a suitable thickness is a positive modification to obtain high-performance GdBCO bulk.
钆钡铜氧（GdBaCuO，GdBCO或Gd123）超导块材的临界电流密度性能对其实际应用具有重要影响。在本工作中，采用改进的顶部籽晶熔盐织构生长法成功制备了4个单畴GdBCO超导块材。引入不同厚度（0 mm（S0）、3 mm（S3）、5 mm（S5）、7 mm（S7））的钇钡铜氧（YBaCuO，Y123）液态源，研究其对超导性能的影响。添加3 mm厚Y123液态源的GdBCO块材表现出最佳的超导性能。Y123液态源的添加导致Gd123生长所需的钆离子浓度降低；因此，液态源中的钆钡铜氧（Gd211）颗粒需要更大程度的自分解，以便将钆离子扩散到Gd123生长前沿，这细化了Gd211颗粒的尺寸，并使其在块材中均匀分布。因此，细化的Gd211颗粒产生了更多的钉扎中心，从而提高了GdBCO块材的超导性能。随着Y123液态源厚度增加到5 mm和7 mm，高稀土（钆和钇）浓度会使Gd211颗粒粗化，并与Gd211液态源融合。超导性能明显下降。因此，添加合适厚度的Y123液态源是获得高性能GdBCO块材的一种积极改性方法。
