Record-High Superconductivity in Niobium-Titanium Alloy

• Main Authors: Guo, Jing, Lin, Gongchang, Cai, Shu, Xi, Chuanying, Zhang, Changjin, Sun, Wanshuo, Wang, Qiuliang, Yang, Ke, Li, Aiguo, Wu, Qi, Zhang, Yuheng, Xiang, Tao, Cava, Robert J, Sun, Liling
• Format: Journal Article
• Language: English
• Published: 22-08-2018
• Subjects: Physics - Superconductivity
• DOI: 10.48550/arxiv.1808.07215

Advanced Materials 31(2019)1807240 Here we report the observation of extraordinary superconductivity in a
pressurized commercial niobium-titanium alloy. We find that its zero-resistance
superconductivity persists from ambient pressure to the pressure as high as
261.7 GPa, a record high pressure up to which a known superconducting state can
continuously survives. Remarkably, at such an ultra-high pressure, although the
ambient pressure volume is shrunk by 45% without structural phase transition,
the superconducting transition temperature (TC) increases to ~19.1 K from ~9.6
K, and the critical magnetic field (HC2) at 1.8 K has been enhanced to 19 T
from 15.4 T. These results set new records for both of the TC and the HC2 among
all the known alloy superconductors composed of only transition metal elements.
The remarkable high pressure superconducting properties observed in the NbTi
alloy not only expand our knowledge on this important commercial superconductor
but also are helpful for a better understanding on the superconducting
mechanism.