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arXiv · 1907.01776

The Unusual Suppression of Superconducting Transition Temperature in Double-Doping 2H-NbSe$_2$

Dong Yan·Yishi Lin·Guohua Wang·Zhen Zhu·Shu Wang·Lei Shi·Yuan He·Man-Rong Li·Hao Zheng·Jie Ma·Jinfeng Jia·Yihua Wang·Huixia Luo
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Abstract

2H-NbSe2 is one of the most widely researched transition metal dichalcogenide (TMD) superconductors, which undergoes charge-density wave (CDW) transition at TCDW about 33 K and superconducting transition at Tc of 7.3 K. To explore the relation between its superconductivity and Fermi surface nesting, we combined S substitution with Cu intercalation in 2H-NbSe2 to make CuxNbSe2-ySy. Upon systematic substitution of S and intercalation of Cu ions into 2H-NbSe2, we found that when the Cu and S contents increases, the Tc decreases in CuxNbSe2-ySy. While at higher x and y values, Tc keeps a constant value near 2 K, which is not commonly observed for a layered TMD. For comparison, we found the simultaneous substitution of Nb by Cu and Se by S in CuxNb1-xSe2-ySy lowered the Tc substantially faster. We construct a superconducting phase diagrams for our double-doping compounds in contrast with the related single-ions doping systems.

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Dong Yan, Yishi Lin, Guohua Wang, Zhen Zhu, Shu Wang, Lei Shi, Yuan He, Man-Rong Li, Hao Zheng, Jie Ma, Jinfeng Jia, Yihua Wang, Huixia Luo. 2019-07-03. The Unusual Suppression of Superconducting Transition Temperature in Double-Doping 2H-NbSe$_2$. https://doi.org/10.1088/1361-6668%2Fab169d

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