Periodic artificial pinning centers for high critical current density of tape conductor
Periodic artificial pinning centers for high critical current density of tape conductor
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用于带状导体高临界电流密度的周期性人工钉扎中心
DOI：
10.1109/tasc.2002.1018596
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发表时间：
2002
影响因子：
1.8
通讯作者：
T. Hamajima
中科院分区：
文献类型：
--
作者：
H. Yamada;N. Harada;T. Iwamoto;K. Sugai;M. Tsuda;T. Hamajima
超导磁体中的强磁场要求超导带材具有有效的钉扎中心，以获得高的临界电流密度。我们研究了用于高温超导带状导体的周期性人工钉扎中心。在超导Nb膜上引入周期性图案作为人工钉扎中心。在Nb膜上形成不同深度的2和4 μ m/s周期的沟槽图案。具有沟槽图案的薄膜的磁化强度和临界电流密度大于没有图案的薄膜，这是有效的人工钉扎的结果。在考虑由缺陷引起的瞬时磁化后，具有2 /spl μ/m周期凹槽的膜具有约2倍于具有4 /spl μ/m周期凹槽的膜的磁化。计算出2 /spl μ/m周期沟槽图案的钉扎力密度与4 /spl μ/m周期沟槽图案的钉扎力密度之比为2。两种薄膜的磁化强度都随着槽深的增加而增加，直到达到薄膜厚度的一半。认为这种磁化强度随槽深的增加主要是由于单个磁通线的基本钉扎力的增加所致。
For high magnetic field in superconducting magnet, superconducting tape conductor with effective pinning centers is required for high critical current density. We studied periodic artificial pinning centers for use in HTS tape conductor. Periodic patterns were introduced as artificial pinning centers on a superconducting Nb film. 2 and 4 /spl mu/m period groove patterns were formed on the Nb film with various depths. Magnetization and critical current density of the films with the groove patterns were larger than those of the film without the pattern, as a result of effective artificial pinning. After regarding immanent magnetization caused by defects, films with 2 /spl mu/m period grooves had about 2 times as much magnetization as the films with 4 /spl mu/m period grooves. Ratio of pinning force density of 2 /spl mu/m period groove pattern to that of 4 /spl mu/m period groove pattern was calculated to be 2. The magnetization of both films increased with groove depth until it reached a half of film thickness. It is considered that this increase of magnetization with groove depth is mainly caused by an increase of elementary pinning force for individual flux line.