Superior critical current density obtained in (MgB2)-B-11 low activation superconductor by using reactive amorphous B-11 and optimizing sintering temperature

作者：Cheng Fang; Liu Yongchang; Ma Zongqing^*; Li Huijun; Al Hossain M Shahriar

来源：Journal of Alloys and Compounds, 2015, 650: 508-513.

DOI：10.1016/j.jallcom.2015.08.022

• MgB2 superconductor
• Isotope
• Cu doping
• Critical current density

The un-doped (MgB2)-B-11 and Cu-doped (MgB2)-B-11 bulks using B-11 as a boron precursor were fabricated by solid-state reaction and sintered at different temperature in present work. By analyzing the sintering process, it was found that B-11 original powder is more reactive and can react with Mg severely even at low temperature before Mg melting, which leads to the formation of refined (MgB2)-B-11 grains. Consequently, the critical current density of (MgB2)-B-11 sample prepared in this work is higher than that of natural MgB2. Furthermore, it was found that proper Cu addition could obviously accelerate the reaction between Mg and B-11 and promote the formation of (MgB2)-B-11 due to the appearance of Mg-Cu liquid at low sintering temperature before Mg melting. On the other hand, Cu addition also introduced more MgCu(2)impurity, leading to a relatively lower critical current density on the whole. Interestingly, the critical current density of the Cu doped sample sintered at 800 degrees C is surprisingly enhanced at the low field, compared with that of the corresponding un-doped one. This is due to the peritectic reaction which generated small-sized MgCu2 occurred that at 800 degrees C, providing MgCu2 pinning centers well-distributed in the MgB2 matrix.

• 出版日期2015-11-25
• 单位天津大学