Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）....Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）. There have been comprehensive and intensive studies on the applications, the fundamental lattice dynamic and electronic properties, etc., of A15 superconductors. Various reviews on the preparations, structures, and properties have already been written in the last few years. Nevertheless, on account of the large amount of existing facts and views, a coherent view on the relations between the structures and properties has not appeared to unify the facts. This article sketches a multi-scale point of view on the relations between the multi- scale structures and the corresponding properties.展开更多
Four sets of mono-element (ME) and two kinds of multifilament (MF) internal-Sn Nb3Sn superconducting strands were designed and fabricated through RRP method in which different compoment ratios, various composite confi...Four sets of mono-element (ME) and two kinds of multifilament (MF) internal-Sn Nb3Sn superconducting strands were designed and fabricated through RRP method in which different compoment ratios, various composite configurations and some third element alloying were arranged. All the strand samples underwent a 210°C/50 h + 340°C/25 h thermal duration for Cu-Sn alloying. After that A15 phase formation heat treatment (HT) was applied for which the ME samples were chosen at three reaction temperatures of 675°C, 700°C and 725°C for 100 h and 200 h while the MF samples at four temperatures of 650°C, 675°C, 700°C and 725°C for 128 h and 200 h. The heat-treated samples were examined for A15 phase composition distribution by X-ray EDS. SQUID magnetization measurement was used to determine critical temperature TC. The obtained results demonstrate that for fully-reacted internal-Sn Nb3Sn superconductors the A15 phase composition and the intrinsic property TC are determined by the diffusion and solid state reaction mechanism and are independent of the factors including HT temperature, strand composite component and configuration arrangement, and the third element addition within the experimental range.展开更多
基金financially supported by the Science Foundation for International Cooperation of Sichuan Province (2014HH0016)the Fundamental Research Funds for the Central Universities (SWJTU2014: A0920502051113-10000)National Magnetic Confinement Fusion Science Program (2011GB112001)
文摘Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）. There have been comprehensive and intensive studies on the applications, the fundamental lattice dynamic and electronic properties, etc., of A15 superconductors. Various reviews on the preparations, structures, and properties have already been written in the last few years. Nevertheless, on account of the large amount of existing facts and views, a coherent view on the relations between the structures and properties has not appeared to unify the facts. This article sketches a multi-scale point of view on the relations between the multi- scale structures and the corresponding properties.
基金supported by the France-China Collaboration Research Contract: CNRS No722441the SUST doctoral foundation BJ07-07
文摘Four sets of mono-element (ME) and two kinds of multifilament (MF) internal-Sn Nb3Sn superconducting strands were designed and fabricated through RRP method in which different compoment ratios, various composite configurations and some third element alloying were arranged. All the strand samples underwent a 210°C/50 h + 340°C/25 h thermal duration for Cu-Sn alloying. After that A15 phase formation heat treatment (HT) was applied for which the ME samples were chosen at three reaction temperatures of 675°C, 700°C and 725°C for 100 h and 200 h while the MF samples at four temperatures of 650°C, 675°C, 700°C and 725°C for 128 h and 200 h. The heat-treated samples were examined for A15 phase composition distribution by X-ray EDS. SQUID magnetization measurement was used to determine critical temperature TC. The obtained results demonstrate that for fully-reacted internal-Sn Nb3Sn superconductors the A15 phase composition and the intrinsic property TC are determined by the diffusion and solid state reaction mechanism and are independent of the factors including HT temperature, strand composite component and configuration arrangement, and the third element addition within the experimental range.
