Structural sequence and superconductivity in high-entropy Mo-W-Re-Ru-Pd alloys

• Published in: Scripta materialia Vol. 243; p. 115986
• Main Authors: Xu, Xiao, Yang, Wuzhang, Song, Hongyuan, Wang, Jingsong, Yu, Lan, Ren, Zhi, Liu, Bin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2024
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/j.scriptamat.2024.115986

The evolution of crystal structure and physical properties with the variation of chemical composition in series of Mo35WxReyRuzPd5 high-entropy alloys (HEAs) have been investigated. A bcc→σ-type→ hcp structural sequence is observed and driven by increasing d-band occupation nd. All HEAs consist of a single solid solution phase and undergo a bulk superconducting transition. The transition temperature Tc increases with increasing nd up to 8.32 K, and displays a linear dependence on the electron-phonon coupling strength. Furthermore, the overall structural and superconducting behaviors of the Mo35WxReyRuzPd5 HEAs bear striking similarities with the binary Mo1−xRex alloys, except that the Tc in the bcc phase of the former is significantly lower than that of the latter due to the decrease of the electron-phonon matrix element. Our study represents the first observation of sequential structural transformation in HEAs at ambient pressure, and helps to better understand the structure dependent superconducting characteristics in strongly disordered systems.