Significant Improvement of Superconducting Properties in Nano‐NiFe2O4‐Doped Y–Ba–Cu–O Single‐Grain Superconductor
Significant Improvement of Superconducting Properties in Nano‐NiFe2O4‐Doped Y–Ba–Cu–O Single‐Grain Superconductor
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DOI：
10.1111/jace.14035
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发表时间：
2016-02
影响因子：
3.9
通讯作者：
Guo-Zheng Li;Lei Dong;Xiangyun Deng
中科院分区：
文献类型：
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作者：
Guo-Zheng Li;Lei Dong;Xiangyun Deng
在超导YBa2Cu3O7−x（Y‐123）基体中引入细化的第二相粒子是改善Y - ba - cu - o （YBCO）单晶超导体δl型钉钉和性能的有效途径，而由基体成分的空间波动引起的δTc型钉钉也很重要，有助于块状超导体的场内djc性能和高场应用。在这篇文章中，我们使用一种基于纳米Y2O3+ BaCuO2固体源颗粒（SSP）的新型顶种渗透生长（TSIG）技术，在单粒YBCO超导体中化学掺杂纳米尺寸的NiFe2O4（平均尺寸为50 nm）。结果表明，与未掺杂的样品（28.81 N和0.2754 T）相比，掺量为0.2 wt%的纳米NiFe2O4样品的悬浮力（33.93 N）和捕获场（0.3628 T）均有显著提高。测量结果表明，NiFe2O4掺杂样品的onsetta减小了约87.5 K，跃迁宽度变宽了约5k，表明Y - 123晶格中Ni和Fe的取代导致超导基体中出现了弱超导区。本研究提供了一种显著提高YBCO本体性能的实用方法。
Introduction of refined second‐phase particles in superconducting YBa2Cu3O7−x(Y‐123) matrix is known to be an effective route to improve the δl‐type pinning and the performance of Y–Ba–Cu–O (YBCO) single‐grain superconductors, while the δTc‐type pinning induced by spatial fluctuations in matrix composition is also important and contributes to the in‐fieldJcperformance and high‐field applications of bulk superconductors. In this communication, chemical doping of nano‐sized NiFe2O4(mean size 50 nm) in single‐grain YBCO superconductor is performed using a novel top‐seeded infiltration growth (TSIG) technique based on a solid source pellet (SSP) of nano‐Y2O3+ BaCuO2. The results indicate that, significant improvement of bulk performances including levitation force (33.93 N) and trapped field (0.3628 T) has been observed in the 0.2 wt% nano‐NiFe2O4‐doped sample, which are much higher than the undoped sample (28.81 N and 0.2754 T).Tcmeasurement indicates that, a decreased onsetTcof about 87.5 K and a broadened transition width of about 5 K are observed in the NiFe2O4‐doped sample, indicating appearance of weak superconducting regions in superconducting matrix caused by Ni and Fe substitutions in Y‐123 crystal lattice. This study supplies a practical approach to increase the YBCO bulk performance significantly.