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

Xi Feng Pan; Guo Yan; Xiang Hong Liu; Yong Feng; Ping Xiang Zhang; Yong Zhao; Akiyoshi Mastumoto; Hiroshi Kumakura

doi:10.4028/www.scientific.net/MSF.745-746.208

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HomeMaterials Science ForumMaterials Science Forum Vols. 745-746Degradation of Porosity and Enhanced Critical...

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

Abstract:

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 nanosized 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, J_c and irreversible fields Birr of MgB₂ are significantly improved. For the best sample, at 20K, 4T and 10K, 6T, the J_c 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.

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Materials Science Forum (Volumes 745-746)

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208-213

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.745-746.208

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Online since:

February 2013

Authors:

Xi Feng Pan, Guo Yan, Xiang Hong Liu, Yong Feng, Ping Xiang Zhang, Yong Zhao, Akiyoshi Mastumoto, Hiroshi Kumakura

Keywords:

Critical Current Density, Flux Pinning, MgB₂, Porosity

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