Superconductivity in Cubic A15-type V–Nb–Mo–Ir–Pt High-Entropy Alloys
Bin Liu, Jifeng Wu, Yanwei Cui, Qinqing Zhu, Guorui Xiao, Siqi Wu, Guang‐Han Cao, Zhi Ren
Abstract
We report the crystal structure and superconducting properties of new V 5+2 x Nb 35− x Mo 35− x Ir 10 Pt 15 high-entropy alloys (HEAs) for x in the range of 0 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="minf1"><mml:mo>≤</mml:mo></mml:math> x <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="minf2"><mml:mo>≤</mml:mo></mml:math> 10. These HEAs are found to crystallize in a cubic A15-type structure and have a weakly coupled, fully gapped superconducting state. A maximum T c of 5.18 K and zero-temperature upper critical field <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="minf3"><mml:mrow><mml:msub><mml:mi>B</mml:mi><mml:mrow><mml:mtext>c</mml:mtext><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> (0) of 6.4 T are observed at x = 0, and both quantities decrease monotonically with the increase of V content x . In addition, T c shows an increase with increasing valence electron concentration from 6.4 to 6.5, which is compared with other A15-type HEA and binary superconductors.