Degradation of Porosity and Enhanced Critical Current Density in MgB2 with a Toluene-treatment Boron Powder

摘要：

　　A series of MgB2 bulks with different porosity have been successfully prepared by in-situ solid-state reaction at ambient pressure with a toluene-treatment boron powder.The mass density reaches 1.86 g cm-3 at the most compact MgB2 bulk,which has an imporous microstructure,excellent grains coupling,clean grain boundaries and nano-sized grains (100~200 nm).Our results reveal that the porosity of MgB2 can be significantly depressed by tuning the residual toluene content and heat treatment temperature in this way.Due to the degradation of porosity and thus the enhancement on grains connectivity and grains boundary pinning,the critical current density,Jc and irreversible fields Birr of MgB2 are significantly improved.For the best sample,at 20K,4T and 10K,6T,the Jc reach 2400 and 3700 A cm-2,which is higher than normal porous sample by a factor of 20 and 8,respectively;and the Birr at 20 K reaches 5.10 T.

关键词： MgB2 Critical current density Flux pinning Porosity

作者: Xifeng Pan Guo Yan Xianghong Liu Yong Feng Pingxiang Zhang Yong Zhao Akiyoshi Mastumoto Hiroshi Kumakura

作者单位: Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Superconductivity and New ener National engineering laboratory for superconducting materials,Western Superconducting Technologies C National Institute for Materials Science, Superconducting Materials Center, 1-2-1,Sengen, Tsukuba, I

会议类型: 国际会议

会议名称: the Chinese Materials Congress 2012(2012年中国材料大会(CMC2012))

会议地点: 太原

会议语种:英文

页码: 208-213

在线出版日期: 2012-07-13（万方平台首次上网日期，不代表论文的发表时间）