{"title":"Strong electron–phonon coupling and predicted high superconducting transition temperature of MXenes revealed in 2H-Mo2N under biaxial stress","authors":"","doi":"10.1016/j.physb.2024.416551","DOIUrl":null,"url":null,"abstract":"<div><div>Extensive investigations have been conducted on Mo-based MXenes due to their high superconducting temperatures (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>). This work theoretically reports strong electron–phonon coupling (EPC) and high <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> (<span><math><mo>≈</mo></math></span>38 K) of 2H-Mo<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>N under biaxial stress, with excellent mechanical properties. EPC and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> are elucidated upon dynamically stable strain range. At 0% strain, EPC constant (<span><math><mi>λ</mi></math></span>) and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> are 1.32 and 22.7 K, respectively. They are improved when subjected to biaxial stresses. Strong EPC with <span><math><mi>λ</mi></math></span> over 2.0 occurs at −4%, −2.5%, and 5% strains, yielding enhanced <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>. The finding suggests that the energy levels of electronic bands at the Fermi level are enhanced by strain, which enhances EPC. Moreover, the impact of functional groups on superconductivity has been investigated. The <span><math><mi>λ</mi></math></span>’s of Mo<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>NH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and Mo<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>NO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> are reduced, and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> drops nearly to 20.0 and 0.9 K, respectively. This work provides an example of designing 2D superconductors by tuning atomic recipes and strain-dependent engineering.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physica B-condensed Matter","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921452624008925","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
Extensive investigations have been conducted on Mo-based MXenes due to their high superconducting temperatures (). This work theoretically reports strong electron–phonon coupling (EPC) and high (38 K) of 2H-MoN under biaxial stress, with excellent mechanical properties. EPC and are elucidated upon dynamically stable strain range. At 0% strain, EPC constant () and are 1.32 and 22.7 K, respectively. They are improved when subjected to biaxial stresses. Strong EPC with over 2.0 occurs at −4%, −2.5%, and 5% strains, yielding enhanced . The finding suggests that the energy levels of electronic bands at the Fermi level are enhanced by strain, which enhances EPC. Moreover, the impact of functional groups on superconductivity has been investigated. The ’s of MoNH and MoNO are reduced, and drops nearly to 20.0 and 0.9 K, respectively. This work provides an example of designing 2D superconductors by tuning atomic recipes and strain-dependent engineering.
期刊介绍:
Physica B: Condensed Matter comprises all condensed matter and material physics that involve theoretical, computational and experimental work.
Papers should contain further developments and a proper discussion on the physics of experimental or theoretical results in one of the following areas:
-Magnetism
-Materials physics
-Nanostructures and nanomaterials
-Optics and optical materials
-Quantum materials
-Semiconductors
-Strongly correlated systems
-Superconductivity
-Surfaces and interfaces