Low-frequency conductivity of low wear high-entropy alloys

Cheng-Hsien Yeh; Wen-Dung Hsu; Bernard Haochih Liu; Chan-Shan Yang; Chen-Yun Kuan; Yuan-Chun Chang; Kai-Sheng Huang; Song-Syun Jhang; Chia-Yen Lu; Peter K Liaw; Chuan-Feng Shih

doi:10.1038/s41467-024-49035-0

Low-frequency conductivity of low wear high-entropy alloys

Nat Commun. 2024 May 29;15(1):4554. doi: 10.1038/s41467-024-49035-0.

Authors

Cheng-Hsien Yeh¹, Wen-Dung Hsu^{2

3

4}, Bernard Haochih Liu^{5

6}, Chan-Shan Yang^{7

8}, Chen-Yun Kuan⁹, Yuan-Chun Chang⁹, Kai-Sheng Huang⁹, Song-Syun Jhang⁹, Chia-Yen Lu¹⁰, Peter K Liaw¹¹, Chuan-Feng Shih^{12

13

14}

Affiliations

¹ Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan.
² Department of Materials Science and Engineering, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
³ Applied High Entropy Technology (AHET) Center, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
⁴ Program on Semiconductor Packaging and Testing, Academy of Innovative Semiconductor and Sustainable Manufacture, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
⁵ Department of Materials Science and Engineering, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
⁶ Applied High Entropy Technology (AHET) Center, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
⁷ Applied High Entropy Technology (AHET) Center, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
⁸ Institute and Undergraduate Program of Electro-Optical Engineering, National Taiwan Normal University, Taipei, 11677, Taiwan. [email protected].
⁹ Department of Materials Science and Engineering, National Cheng Kung University, Tainan, 70101, Taiwan.
¹⁰ Institute and Undergraduate Program of Electro-Optical Engineering, National Taiwan Normal University, Taipei, 11677, Taiwan.
¹¹ Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN, 37996, USA.
¹² Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
¹³ Applied High Entropy Technology (AHET) Center, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].
¹⁴ Program on Semiconductor Packaging and Testing, Academy of Innovative Semiconductor and Sustainable Manufacture, National Cheng Kung University, Tainan, 70101, Taiwan. [email protected].

Abstract

High-entropy alloys (HEAs) provide new research avenues for alloy combinations in the periodic table, opening numerous possibilities in novel-alloy applications. However, their electrical characteristics have been relatively underexplored. The challenge in establishing an HEA electrical conductivity model lies in the changes in electronic characteristics caused by lattice distortion and complexity of nanostructures. Here we show a low-frequency electrical conductivity model for the Nb-Mo-Ta-W HEA system. The cocktail effect is found to explain trends in electrical-conductivity changes in HEAs, while the magnitude of the reduction is understood by the calculated plasma frequency, free electron density, and measured relaxation time by terahertz spectroscopy. As a result, the refractory HEA Nb₁₅Mo₃₅Ta₁₅W₃₅ thin film exhibits both high hardness and excellent conductivity. This combination of Nb₁₅Mo₃₅Ta₁₅W₃₅ makes it suitable for applications in atomic force microscopy probe coating, significantly improving their wear resistance and atomic-scale image resolution.

Abstract

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