东北大学学报(自然科学版) ›› 2025, Vol. 46 ›› Issue (8): 156-162.DOI: 10.12068/j.issn.1005-3026.2025.20240237

• 研究论文 • 上一篇    

拓扑节线材料Fe4C中反常热电效应的理论预测

陈荣1,2, 于天野2, 陈星秋2, 孙岩2   

  1. 1.东北大学 材料科学与工程学院,辽宁 沈阳 110819
    2.中国科学院金属研究所 沈阳材料科学国家研究中心,辽宁 沈阳 110016
  • 收稿日期:2024-12-26 出版日期:2025-08-15 发布日期:2025-11-24
  • 通讯作者: 于天野
  • 作者简介:陈 荣(1997—),男,重庆潼南人,东北大学博士研究生
    孙 岩(1983—),男,河北保定人,中国科学院金属研究所研究员,博士生导师.
  • 基金资助:
    国家自然科学基金资助项目(52271016);辽宁省兴辽英才计划项目(XLYC2203080)

Theoretical Prediction of Anomalous Thermoelectric Effects in Topological Nodal Line Material Fe₄C

Rong CHEN1,2, Tian-ye YU2, Xing-qiu CHEN2, Yan SUN2   

  1. 1.School of Material Science & Engineering,Northeastern University,Shenyang 110819,China
    2.Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China.
  • Received:2024-12-26 Online:2025-08-15 Published:2025-11-24
  • Contact: Tian-ye YU

摘要:

寻找具有室温应用潜力的反常能斯特电导率大的材料对于热电器件的发展至关重要.拓扑磁性材料由于具有特殊的电子结构,可以表现出比传统磁性材料更强的反常霍尔电导率和反常能斯特电导率.通过第一性原理计算对Fe₄C化合物的热电效应进行了详细研究.结果表明,外磁场的引入破坏了不同镜面上由对称性保护的节线环以及在某些高对称路径上的节线,由此产生较大的本征贝里曲率是Fe₄C化合物具有显著反常霍尔电导率和反常能斯特电导率的主要原因.这一发现揭示了晶体对称性与材料本征贝里曲率之间的强关联性.此外,温度依赖的反常能斯特电导率曲线表明了Fe₄C化合物具有室温应用潜力.以上结果有助于全面理解Fe₄C化合物的热电效应及其应用.

关键词: 热电效应, 第一性原理计算, 贝里曲率, 反常霍尔效应, 反常能斯特效应

Abstract:

The search for materials with large anomalous Nernst conductivity at room temperature is crucial for the development of thermoelectric devices. Topological magnetic materials, due to their unique electronic structures, can exhibit bigger anomalous Hall conductivity and anomalous Nernst conductivity compared to conventional magnetic materials. The thermoelectric effects of the Fe4C compound have been studied through first-principles calculations. The results show that the introduction of an external magnetic field breaks symmetry-protected nodal line rings on various mirrors, as well as nodal lines on certain high-symmetry paths, leading to a significant intrinsic Berry curvature. This large intrinsic Berry curvature is the main reason for the substantial anomalous Hall conductivity and anomalous Nernst conductivity of the Fe4C compound. This finding highlights the strong correlation between crystal symmetry and the intrinsic Berry curvature of the material. Additionally, the temperature-dependent anomalous Nernst conductivity curve shows the potential of the Fe4C compound for applications at room temperature. These results contribute to a comprehensive understanding of the thermoelectric effects in Fe4C compounds and their further applications.

Key words: thermoelectric effect, first-principles calculation, Berry curvature, anomalous Hall effect, anomalous Nernst effect

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