Record-High Tc and Dome-Shaped Superconductivity in a Medium-Entropy Alloy TaNbHfZr under Pressure up to 160 GPa

Liyunxiao Wu; Jianguo Si; Shixue Guan; He Zhang; Jie Dou; Jun Luo; Jie Yang; Hui Yu; Jiawei Zhang; Xiaoli Ma; Pengtao Yang; Rui Zhou; Miao Liu; Fang Hong; Xiaohui Yu

doi:10.1103/PhysRevLett.132.166002

Record-High Tc and Dome-Shaped Superconductivity in a Medium-Entropy Alloy TaNbHfZr under Pressure up to 160 GPa

Liyunxiao Wu, Jianguo Si, Shixue Guan, He Zhang, Jie Dou, Jun Luo, Jie Yang, Hui Yu, Jiawei Zhang, Xiaoli Ma, Pengtao Yang, Rui Zhou, Miao Liu, Fang Hong, Xiaohui Yu

DOI 10.1103/PhysRevLett.132.166002 · Physical Review Letters

T1

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Abstract

Superconductivity has been one of the focal points in medium and high-entropy alloys (MEAs-HEAs) since the discovery of the body-centered cubic (bcc) HEA superconductor in 2014. Until now, the superconducting transition temperature (Tc) of most MEA and HEA superconductors has not exceeded 10 K. Here, we report a TaNbHfZr bulk MEA superconductor crystallized in the BCC structure with a Tc of 15.3 K which set a new record. During compression, Tc follows a dome-shaped curve. It reaches a broad maximum of roughly 15 K at around 70 GPa before decreasing to 9.3 K at 157.2 GPa. First-principles calculations attribute the dome-shaped curve to two competing effects, that is, the enhancement of the logarithmically averaged characteristic phonon frequency ωlog and the simultaneous suppression of the electron-phonon coupling constant λ. Thus, TaNbHfZr MEA may have a promising future for studying the underlying quantum physics, as well as developing new applications under extreme conditions.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
TaNbHfZr Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	8.1	Pressure unresolved	unknown
TaNbHfZr Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	8.5	1.8 GPa	onset
TaNbHfZr Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	14	43.4 GPa	onset
TaNbHfZr Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	15.3	71.6 GPa	onset
TaNbHfZr Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	9.3	157.2 GPa	onset
TaNbHfZr Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	13.2	50 GPa	unknown
(TaNb)0.67(HfZrTi)0.33 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	7.7	Pressure unresolved	unknown
(ScZrNbTa)0.6(RhPd)0.4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	12.5	30 GPa	unknown