Improving flux pinning at high fields in intermetallic superconductors:: Clues from MgB2 and MgCNi3

被引：13

作者：

Cooley, L ^{[1
]}

Song, XY ^{[1
]}

Larbalestier, D ^{[1
]}

机构：

[1] Univ Wisconsin, Ctr Appl Supercond, Madison, WI 53706 USA

来源：

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY | 2003年 / 13卷 / 02期

关键词：

critical current density; flux pinning; intermetallic superconductors; magnesium diboride;

D O I：

10.1109/TASC.2003.812225

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

We discuss flux pinning and nanostructural analyzes of two intermetallic superconductors that exhibit substantial deviations from the usual flux-shear behavior. Kramer plots for a MgB2 thin film, which contained a substantial fraction of MgO nanoprecipitates, show an additional component that is attributed to core pinning by the precipitates. Also, polycrystalline MgCNi3 displays a crossover from flux-shear to core pinning behavior as the temperature is reduced. At the same time, the flux line core diameter becomes comparable to the length scales of nanoprecipitates found by high-resolution electron microscopy. Thus, both experiments suggest that flux shear, and its low-field pinning characteristic, can be exceeded by incorporating nanoprecipitates in an intermetallic superconductor. However, too many precipitates within the grain boundaries can block uniform current flow between grains.

引用

页码：3280 / 3283

页数：4

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