Materials (Aug 2023)

Enhanced Superconducting Critical Parameters in a New High-Entropy Alloy Nb<sub>0.34</sub>Ti<sub>0.33</sub>Zr<sub>0.14</sub>Ta<sub>0.11</sub>Hf<sub>0.08</sub>

  • Rafał Idczak,
  • Wojciech Nowak,
  • Bartosz Rusin,
  • Rafał Topolnicki,
  • Tomasz Ossowski,
  • Michał Babij,
  • Adam Pikul

DOI
https://doi.org/10.3390/ma16175814
Journal volume & issue
Vol. 16, no. 17
p. 5814

Abstract

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The structural and physical properties of the new titanium- and niobium-rich type-A high-entropy alloy (HEA) superconductor Nb0.34Ti0.33Zr0.14Ta0.11Hf0.08 (in at.%) were studied by X-ray powder diffraction, energy dispersive X-ray spectroscopy, magnetization, electrical resistivity, and specific heat measurements. In addition, electronic structure calculations were performed using two complementary methods: the Korringa–Kohn–Rostoker Coherent Potential Approximation (KKR-CPA) and the Projector Augmented Wave (PAW) within Density Functional Theory (DFT). The results obtained indicate that the alloy exhibits type II superconductivity with a critical temperature close to 7.5 K, an intermediate electron–phonon coupling, and an upper critical field of 12.2(1) T. This finding indicates that Nb0.34Ti0.33Zr0.14Ta0.11Hf0.08 has one of the highest upper critical fields among all known HEA superconductors.

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