V-I characteristics of MgB2 PIT composite tapes:: n-values under strain, in high fields, or at high temperatures
V-I characteristics of MgB2 PIT composite tapes:: n-values under strain, in high fields, or at high temperatures
复制标题
DOI：
10.1016/j.physc.2003.09.047
复制
发表时间：
2004-01-15
影响因子：
1.7
通讯作者：
Kumakura, H
中科院分区：
文献类型：
--
作者：
Kitaguchi, H;Matsumoto, A;Kumakura, H
研究了单芯MgB 2 PIT复合带材在应变、高场和高温下的n值V-I特性。n值通过使用由直流四探针电阻法获得的短样品的V-I曲线来确定。n值随着外部拉伸应变的增加而增加，直到0.5%，其方式与临界电流I-c随着应变的增加而增加相同。当应变超过0.5%时，I-c和n值出现较大的下降。在高场测试中，原位处理的MgB 2（+10 at.% SiC）带在10、12和16 T下分别显示出25.8-29.0（J（c）（芯）= 12，000 - 15，000 A/ cm（2））、18.3-20.1（5300-6200 A/cm（2））和4.8-6.5（970-1100 A/cm（2））的n值。在高温测试中，带材在4 T中的18 K、3 T中的21 K、2 T中的25.5K和1 T中的29 K下显示出约40的n值。I-c和n值表现出很强的相关性。具有较大I-c的MgB 2导体可以导致较高的n值。(C)2003 Elsevier B. V.保留所有权利。
V-I characteristics of monocore MgB2 PIT composite tapes are examined in n-values under strain, in high fields, or at high temperatures. n-values are determined by using V-I curves that are obtained for short samples by dc four-probe resistive method. The n-value increases with increasing external tensile strain up to 0.5% in the same way that critical current, I-c, increases with increasing the strain. When the strain exceeds 0.5%, I-c and n-value show a large degradation. In high field tests, in situ processed MgB2(+10 at.% SiC) tapes show n-values of 25.8-29.0 (J(c)(core) = 12,000-15,000 A/ cm(2)), 18.3-20.1 (5300-6200 A/cm(2)), and 4.8-6.5 (970-1100 A/cm(2)) at 10, 12, and 16 T, respectively. In high temperature tests, the tapes show n-values around 40 at 18 K in 4 T, 21 K in 3 T, 25.5 K in 2 T, and 29 K in 1 T. I-c and n-value show a strong correlation. MgB2 conductors with the larger I-c can lead to the higher n-value. (C) 2003 Elsevier B.V. All rights reserved.