华东师范大学学报(自然科学版) ›› 2023, Vol. 2023 ›› Issue (4): 65-73.doi: 10.3969/j.issn.1000-5641.2023.04.007

• 物理学与电子学 • 上一篇    下一篇

应力导致的Fe2CrGe从反铁磁基态到铁磁半金属相变的计算研究

郭锦1(), 胡啸2, 谢文辉1,*()   

  1. 1. 华东师范大学 物理与电子科学学院, 上海 200241
    2. 代尔夫特理工大学 微电子系, 代尔夫特 2628 CD, 荷兰
  • 收稿日期:2021-11-17 出版日期:2023-07-25 发布日期:2023-07-25
  • 通讯作者: 谢文辉 E-mail:1812671535@qq.com;whxie@phy.ecnu.edu.cn
  • 基金资助:
    国家自然科学基金 (51572086)

Computational study on strain-induced transition of Fe2CrGe from an antiferromagnetic ground state to a ferromagnetic half-metal state

Jin GUO1(), Xiao HU2, Wenhui XIE1,*()   

  1. 1. School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
    2. Department of Microelectronics, Delft University of Technology, Delft 2628 CD, Netherlands
  • Received:2021-11-17 Online:2023-07-25 Published:2023-07-25
  • Contact: Wenhui XIE E-mail:1812671535@qq.com;whxie@phy.ecnu.edu.cn

摘要:

运用第一性原理计算研究了惠斯勒(Heusler)合金Fe2CrGe的电子结构和磁性质, 发现其基态是Fe离子处于低自旋态 $(S=0),$ 而Cr离子处于高自旋态 $(S=1)$ 的反铁磁金属相, 反铁磁态能量比铁磁态能量约低0.103 eV. 此外还发现, 如果施加 +1.7%和 –1.7%的应变, Fe2CrGe会从反铁磁有序变成铁磁有序, 并出现半金属特性; 当应变达到±5%时, 出现了大约0.2 eV的半金属能隙. 通过平均场理论估算了Fe2CrGe的居里(Curie)温度, 发现其对应的居里温度为393 K, 远高于室温. 这表明Fe2CrGe是有潜力的自旋电子材料.

关键词: Fe2CrGe, 第一性原理计算, 电子结构, 磁性质

Abstract:

In this study, the electronic structure and magnetism of the Heusler alloy Fe2CrGe are investigated using first-principle calculations. Results show that the ground state of Fe2CrGe is antiferromagnetic metal in which Fe ion and Cr ion are in low- and high-spin states of $ S=0 $ and $ S=1 $ , respectively. The energy of the antiferromagnetic state is approximately 0.103 eV less than that of the ferromagnetic state. In addition, when a tetragonal strain is applied to Fe2CrGe, a transition from antiferromagnetic to ferromagnetic material occurs at +1.7% and –1.7% strains, and Fe2CrGe becomes a ferromagnetic half-metal. A half-metal energy gap of approximately 0.2 eV occurs when the strain reaches ±5%. The Curie temperature of Fe2CrGe is estimated to be 393 K, which is much higher than room temperature, indicating that Fe2CrGe may be a potential candidate for spintronic applications.

Key words: Fe2CrGe, first-principle calculation, electronic structure, magnetic properties

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