Physica Status Solidi-Rapid Research Letters
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2020
·Vol. 15
·期 4
·2000563
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IF 2.291
Xinhua Li,Qingshuang Ma,Ji Dong,Tansir Ahamad,Zongqing Ma
The Nb 3 (Al 1− x Sn x ) superconductor with enhanced critical current density ( J c ) is prepared by the process of mechanical alloying (MA) and subsequent low-temperature sintering and the enhancement mechanism of J c in Nb 3 (Al 1− x Sn x ) is discussed. The analysis of the flux pinning force implies that there is an additional pinning mechanism apart from grain boundary pinning in Nb 3 (Al 1− x Sn x ). The existence of dispersed Nb 2 Al nanoparticles (<30 nm) in Nb 3 (Al 1− x Sn x ) is confirmed by microstructure observation. These nanosized Nb 2 Al particles can serve as flux pinning centers, which leads to the increase of the flux pinning force as well as the enhancement of Nb 3 (Al 1− x Sn x )'s J c performance.
研究领域:
材料科学
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超导研究
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产品关联
DOI
高影响因子
INTERMETALLICS
·
2020
·
IF 3.398
Xinhua Li,Feng Lan,Xin Wen,Huanhuan Zhao,Qingshuang Ma,Zhu Qian,Lei Ma,Zongqing Ma,Yongchang Liu
The Nb 3 (Al 1-x Sn x ) superconductors (x = 0.05, 0.15, 0.25, 0.35) were prepared by mechanical alloying and subsequent low-temperature sintering. It was found that the critical current density ( J c ) of the obtained Nb 3 (Al 1-x Sn x ) sample is enhanced significantly compared to undoped Nb 3 Al prepared using the same method. The maximum value of the J c reaches up to 5.10 × 10 4 A·cm −2 (4.2 K, 5 T) for Nb 3 (Al 0.85 Sn 0.15 ) sample. Combined with the phase composition analysis and microstructure observation, it is indicated that Sn enters the A15 crystal structure of Nb 3 Al forming the Nb 3 (Al 1-x Sn x ) phase after low-temperature sintering. What's more, Sn doping improves the grain connectivity as well as refines the grain size of Nb 3 Al, which are the main reasons for the enhancement of J c in the Sn doped samples. Based on the exploration of the phase evolution of Nb–Al–Sn system during the mechanical alloying and subsequent low-temperature sintering process, it is also confirmed that Nb 3 Sn forms firstly during the sintering process and then can serve as the perfect nucleus of Nb 3 Al to increase its nucleation rate, leading to the significant decrease of the grain size of Nb 3 Al.
研究领域:
材料科学
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超导体研究
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DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2024
·Vol. 131
·期 1
·1-7
·
IF 2.5
Guo Yiming,Zhang Lei,Zhao Yong,Huang Mei,Xu Min,Zhang Yong
This research employed the powder-in-tube (PIT) method to facilitate the introduction of the non-metallic element iodine (I) into the preparation of Nb 3 Al superconducting wires. After heating in a tube furnace, a rapid heating, quenching, and transformation (RHQT) treatment was conducted. It was observed that as the quantity of iodine introduced increased, the extent of the Nb/Al reaction also rose, indicating that a certain amount of iodine can be introduced to facilitate the Nb/Al reaction, thereby enabling Nb to react more fully with Al in the subsequent process and generating a Nb 3 Al superconducting phase that is closer to the stoichiometric ratio. Wires with iodine contents of 1.0 wt%, 1.5 wt%, and 2.0 wt% exhibited a diffusion layer at the Nb/Al interface after heating in a tube furnace at 1000 °C for 30 min. The primary component of the diffusion layer was Nb 2 Al. No diffusion layer was observed in the pure sample or in the group with 0.5 wt% I. However, a eutectic phase was present at the edge of Nb and Al. The wires with 1.0 wt% and 1.5 wt% I exhibited higher critical temperatures ( T c ) of 18.236 K and 17.421 K, respectively, than the pure sample. Additionally, they demonstrated superior critical current density ( J c ) properties compared to the pure sample.
研究领域:
材料科学
·
超导研究
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Yaqi He,Xinhua Li,Zhu Qian,ZuPeng Yan,Guizhen Shi,Xia Sun,Zongqing Ma
In this paper, we innovatively introduced Sn and B into the Nb-Al system at the same time and successfully prepared high-performance Nb 3 Al bulks through mechanical alloying and subsequent low-temperature sintering processes. The influence of different doping amounts of B in the Sn-B co-doping on the superconducting properties of Nb 3 Al superconductors was also investigated. It was found that Sn-B co-doping greatly improves the superconducting properties of Nb 3 Al, especially the J c properties, compared with the undoped sample. The optimal doping amount of Sn-B co-doping is finally determined to be 4 at% Sn-2.6 at% B. At this time, the superconducting transition temperature of Nb 3 Al is up to 16.2 K, and the critical current density reaches up to 1.3 × 10 5 A⋅cm −2 (4.2 K, 5 T), which is almost twice higher than that of Sn-doped Nb 3 Al, and one order of magnitude higher than that of general undoped Nb 3 Al. Combined with the phase composition analysis and microstructure observation, we find that with the co-doping of Sn and B, the grain size of Nb 3 Al is refined, and the diffusely distributed Nb 2 Al nanoparticles are introduced, which greatly enhance the magnetic flux pinning effect of Nb 3 Al. Secondly, the intergranular connectivity of Nb 3 Al is significantly improved. The Sn-B co-doped Nb 3 Al superconductors combine the advantages of Sn doping to enhance flux pinning and B doping to improve intergranular connectivity, which synergistically promotes the dramatic improvement of Nb 3 Al superconductivity Nb 3 Al.
研究领域:
材料科学
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超导物理
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金属间化合物
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凝聚态物理
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功能材料
✓ 已验证
产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 4
·1-10
·
IF 2.7
Luo Junsong,Guo Yiming,Liu Lian,Yu Zhou,Zhao Yong,Huang Mei,Xu Min,Duan Xuru,Zhang Yong
Nb 3 (Al 1– x Zn x ) ( x = 0–0.05) wires were obtained after single rapid heating, quenching and low temperature transformation (single-RHQT) process. It is found that Zn element can make crystal plane diffraction peaks of Nb 3 Al phase shift to higher angle, and the interplanar crystal spacing decreases gradually, which indicates that Al atoms in Nb 3 Al lattice are replaced by Zn atoms with smaller diameters. And the addition of Zn can reduce Δ T c and make the superconducting phases purer, and magnetic performances such as critical temperature ( T c ), critical current density ( J c ), irreversible field ( B irr ) are better than that of the pure sample. Nb 3 (Al 0.99 Zn 0.01 ) wire shows the highest J c value of about 5.9 × 10 4 A/cm 2 at 4.2 K and 8 T, and the highest T c value of 16.8 K was found in Nb 3 (Al 0.98 Zn 0.02 ). The influence of multiple rapid heating, quenching and low temperature transformation (multi-RHQT) process on Nb 3 (Al 1– x Zn x ) wires was mainly explored, and 2 at% and 3 at% Zn samples were selected with relatively high Δ T c values for five times RHQT treatment. It is observed that the multi-RHQT process can further reduce Δ T c , and more homogeneous superconducting phases are discovered compared with that of single-RHQT process. The elements are also evenly distributed in the multi-RHQT-processed Nb 3 (Al 1– x Zn x ) wires, leading to the improvement of J c , B irr performances compared to single-RHQT samples. Multi-RHQT-processed Nb 3 (Al 0.98 Zn 0.02 ) and Nb 3 (Al 0.97 Zn 0.03 ) samples show the J c values of 1.7 × 10 5 A/cm 2 and 1.2 × 10 5 A/cm 2 (4.2 K, 8 T), which are nearly ten times as many as that of single-RHQT samples, and Nb 3 (Al 0.97 Zn 0.03 ) has the highest B irr values of 19.6 T (4.2 K) and 10.7 T (10 K). Flux pinning of the Nb 3 (Al 1– x Zn x ) ( x = 0.01–0.05) wires follows the surface pinning mechanism, where grain boundary and stacking faults are considered as pinning centers.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
·
2025
·Vol. 222
·期 22
·2500553
·
IF 1.9
Yaqi He,Xinhua Li,Lihua Zhang,Jiawei Xu,Songhua Chen,Zongqing Ma
In this article, a batch of high-performance Sn-doped Nb 3 Al superconductors is prepared through mechanical alloying and subsequent low-temperature sintering. This article comparatively analyzes the superconducting properties, phase structure, and microstructure of Sn-doped Nb 3 Al under different sintering temperatures and sintering times to determine the most suitable sintering process for Sn-doped Nb 3 Al. The results show that the optimum sintering temperature of Sn-doped Nb 3 Al bulks is 800 °C, with an optimal sintering time of 5 h. The T c value of Sn-doped Nb 3 Al bulk obtained under this sintering condition is 14.8 k, and the value of J c is as high as 6.2 × 10 4 A cm −2 (4.2 K, 5 T). The elevated sintering temperature (900 and 1000 °C) results in significant growth of both Nb 3 Al grain size and Nb 2 Al nanoparticles. This reduces the number of effective pinning centers in the superconducting phase of Sn-doped Nb 3 Al, which severely weakens the flux pinning effect. As a result, the J c performance deteriorates gradually as the sintering temperature increases from 800 to 1000 °C. The extended duration of sintering time results in the formation of sintering holes, which significantly disrupt the continuity of the Nb 3 Al superconducting phase matrix and degrade its superconducting properties.
研究领域:
超导物理
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材料科学
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陶瓷与烧结
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显微组织工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）