Tuning of upper critical field in a vanadium-based A15 superconductor by the compositionally-complex-alloy concept
Tuning of upper critical field in a vanadium-based A15 superconductor by the compositionally-complex-alloy concept
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DOI：
10.1007/s10853-022-07607-9
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发表时间：
2022-08
影响因子：
4.5
通讯作者：
Y. Nakahira;Ryo Kiyama;A. Yamashita;Hiroaki Itou;A. Miura;C. Moriyoshi;Y. Goto;Y. Mizuguchi
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文献类型：
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作者：
Y. Nakahira;Ryo Kiyama;A. Yamashita;Hiroaki Itou;A. Miura;C. Moriyoshi;Y. Goto;Y. Mizuguchi
成分复杂合金是一类新的多主元材料，它与高熵合金密切相关，但合金样品中含有两个以上的相。我们将CCA的概念应用于A_（15）型化合物超导体V_（3X），旨在使Al，Si，Ga，Ge和Sn的混合物占据X位。V3X样品表现出体超导电性，其转变温度Tc为6.3K，接近V3Ge的Tc。由磁化率估算的V3X的上临界场Bc2（0）为8.8T，比V3Ge的上临界场Bc2（0）= 5.8T高约50%。使用同步加速器X射线衍射，揭示了至少五种不同的A15相的存在，这不能通过简单的相分离成V3Al，V3Si，V3Ga，V3Ge和V3Sn来理解。我们认为V3X中的CCA状态导致了Bc2的改善。CCA的概念将有助于改善实际超导体的超导性能。图形摘要
Compositionally complex alloys (CCAs) are a new category of multi-principal-element materials, which are closely related to high-entropy alloys, but contain more than two phases in an alloy sample. We applied the concept of CCA to a A15-type compound superconductor V3Xby aiming to occupy theXsite by a mixture of Al, Si, Ga, Ge and Sn. The V3Xsample showed bulk superconductivity with a transition temperatureTcof 6.3 K, which is close to theTcof V3Ge. The upper critical fieldBc2(0) of V3Xestimated from magnetic susceptibility is 8.8 T, which is ~ 50% higher than that of V3Ge (Bc2(0) = 5.8 T). Using synchrotron X-ray diffraction, the presence of at least five different A15 phases were revealed, which could not be understood by simple phase separation into V3Al, V3Si, V3Ga, V3Ge, and V3Sn. We consider that the CCA states in V3Xresulted in the improvement ofBc2. The CCA concept would be useful for improvement of superconducting properties of practical superconductors.Graphical abstract