High critical current properties of MgB2 bulks prepared by a diffusion method
High critical current properties of MgB2 bulks prepared by a diffusion method
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DOI：
10.1063/1.1939071
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发表时间：
2005-05
影响因子：
4
通讯作者：
S. Ueda;J. Shimoyama;I. Iwayama;A. Yamamoto;Y. Katsura;S. Horii;K. Kishio
中科院分区：
文献类型：
--
作者：
S. Ueda;J. Shimoyama;I. Iwayama;A. Yamamoto;Y. Katsura;S. Horii;K. Kishio
用新开发的PICT扩散法制备了高密度、高纯的硼化镁块材。临界电流密度Jc随样品颗粒尺寸的减小而系统地提高。在自场作用下，在800℃下反应60h，样品的Jc最大，为20K时的0.86 mA/cm~2，比传统的固相反应法制备的多孔∼块材的Jc高近3倍。除了有效电流传递的增加外，30-100 nm的细小颗粒和良好的颗粒连通性导致了JC的显著提高。
Highly dense MgB2 bulks with high purity were synthesized by the newly developed PICT-diffusion method, starting from magnesium and boron which were separately packed in sealed stainless tubes. Critical current density, Jc, systematically improved with a decrease of grain size of the samples. A sample reacted at 800°C for 60h exhibited the highest Jc of ∼0.86MA∕cm2 at 20K in self-field, which was almost three times higher than that of conventional porous MgB2 bulks prepared by the solid-state reaction. Besides an increase of effective current pass, small grains with 30–100nm in size and good grain connectivity resulted in the dramatically enhanced Jc.