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arXiv 2501.02455cond-mat.supr-con
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中熵合金(Ti1/3Hf1/3Ta1/3)1-xNbx中的大上临界场与强耦合超导电性

Large upper critical fields and strong coupling superconductivity in the medium-entropy alloy (Ti1/3Hf1/3Ta1/3)1-xNbx

Longfu Li, Hongyan Tian, Xunwu Hu, Lingyong Zeng, Kuan Li, Peifeng Yu, Kangwang Wang, Rui Chen, Zaichen Xiang, Dao-Xin Yao, Huixia Luo

AI总结:

本文研究BCC结构(Ti0.33Hf0.33Ta0.33)1-xNbx中熵合金的超导电性,发现其具有强耦合s波超导和超过泡利顺磁极限的大上临界场,为理解非常规超导机制提供了新平台。

摘要:

自2014年高熵超导体被发现以来,超导电性一直是中熵和高熵合金(MEAs-HEAs)研究中的焦点之一。本文报道了一系列具有体心立方(BCC)结构的(Ti0.33Hf0.33Ta0.33)1-xNbx中熵合金超导体,并通过电阻率、磁化强度和比热测量对其超导电性进行了表征。研究发现,(Ti0.33Hf0.33Ta0.33)1-xNbx中熵合金表现出体超导电性。随着Nb的掺杂,超导转变温度(Tc)从5.31 K升高至9.11 K,归一化电子比热跳变ΔCel/γTc和对数平均特征声子频率均呈现穹顶形曲线。比热测量结果表明,该体系中的超导电性为强耦合s波类型。此外,在低Nb含量下,样品的上临界场大于泡利顺磁极限。强耦合行为以及s波类型(Ti0.33Hf0.33Ta0.33)1-xNbx中熵合金超导体中出现的较大上临界场并不寻常,因为这些特征通常出现在其他非常规超导体中。因此,(Ti0.33Hf0.33Ta0.33)1-xNbx可能在相关物理机制的研究和理解方面具有重要潜力。

英文摘要:

Since the discovery of high-entropy superconductors in 2014, superconductivity has remained a focal point of interest in medium- and high-entropy alloys (MEAs-HEAs). Here, we report a series of (Ti0.33Hf0.33Ta0.33)1-xNbx MEA superconductors crystallized in the BCC structure, whose superconductivity was characterized by resistivity, magnetization, and specific heat measurements. The study found that the (Ti0.33Hf0.33Ta0.33)1-xNbx MEAs exhibit bulk superconductivity. With the doping of Nb, the superconducting transition temperature (Tc) increases from 5.31 K to 9.11 K, and the normalized Cel jumps at Tc, and the logarithmically averaged characteristic phonon frequency exhibit dome-shaped curves. Results from specific heat measurements indicate that the superconductivity is of a strongly coupled s-wave type observed. Furthermore, at low Nb content, the upper critical field of the samples is larger than the Pauli paramagnetic limit. The strongly coupling behavior and large upper critical field in s-wave type (Ti0.33Hf0.33Ta0.33)1-xNbx MEA superconductors are unusual, as they typically occur in other unconventional superconductors. Thus, (Ti0.33Hf0.33Ta0.33)1-xNbx may have significant potential in the research and understanding of physical mechanisms.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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