中国物理B ›› 2025, Vol. 34 ›› Issue (11): 117105-117105.doi: 10.1088/1674-1056/addbcb

• • 上一篇    下一篇

Swarm-intelligent predictions of high-TC polymorphs in monolayer CrI3 above 77 K

Ying Luo(罗颖)1,2, Shuangyi Xu(许双旖)1,2, Yanan Wang(王亚南)3,4,†, and Yunwei Zhang(张云蔚)1,2,‡   

  1. 1 School of Physics, Sun Yat-sen University, Guangzhou 510275, China;
    2 Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, Guangzhou 510275, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2025-03-25 修回日期:2025-05-13 接受日期:2025-05-22 发布日期:2025-11-13
  • 通讯作者: Yanan Wang, Yunwei Zhang E-mail:wangyanan@sslab.org.cn;zhangyunw@mail.sysu.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant No. 2023YFA1610000), the National Natural Science Foundation of China (Grant Nos. 12304036 and 12304265), the Basic and Applied Basic Research Foundation of Guangdong Province, China (Grant No. 2023A1515010071), and the Fundamental Research Funds for the Central Universities to Sun Yat-sen University (Grant No. 23xkjc016).

Swarm-intelligent predictions of high-TC polymorphs in monolayer CrI3 above 77 K

Ying Luo(罗颖)1,2, Shuangyi Xu(许双旖)1,2, Yanan Wang(王亚南)3,4,†, and Yunwei Zhang(张云蔚)1,2,‡   

  1. 1 School of Physics, Sun Yat-sen University, Guangzhou 510275, China;
    2 Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, Guangzhou 510275, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2025-03-25 Revised:2025-05-13 Accepted:2025-05-22 Published:2025-11-13
  • Contact: Yanan Wang, Yunwei Zhang E-mail:wangyanan@sslab.org.cn;zhangyunw@mail.sysu.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant No. 2023YFA1610000), the National Natural Science Foundation of China (Grant Nos. 12304036 and 12304265), the Basic and Applied Basic Research Foundation of Guangdong Province, China (Grant No. 2023A1515010071), and the Fundamental Research Funds for the Central Universities to Sun Yat-sen University (Grant No. 23xkjc016).

摘要: Monolayer CrI$_{3}$, crystalizing in the $P\bar{3}$1$m$ space group, is a prototypical two-dimensional (2D) material for observing intrinsic ferromagnetic order. However, its relatively low Curie temperature ($T_{\rm C}$) of 45 K severely limits its practical applications, highlighting the need to explore novel metastable polymorphs with enhanced magnetic properties. In this study, we employ a global crystal structure search technique combined with first-principles calculations to systematically investigate new monolayer CrI$_{3}$ phases. Our structural predictions identify two novel polymorphs with Cm and $P2/m$ space groups, both of which are dynamically stable and exhibit significantly higher $T_{\rm C}$ values of 145 K and 81 K, respectively. Electronic property calculations show that the Cm phase is a half-metal, while the $P2/m$ phase is semiconducting with a bandgap of 0.14 eV. Monte Carlo simulations attribute these enhanced $T_{\rm C}$ values to a notable increase in exchange interactions. These findings expand the known phase space of CrI$_{3}$ and provide a promising pathway for designing high-temperature 2D ferromagnets for next-generation spintronic applications.

关键词: chromium triiodide, 2D magnets, structure prediction, first-principles calculations, monolayer structure

Abstract: Monolayer CrI$_{3}$, crystalizing in the $P\bar{3}$1$m$ space group, is a prototypical two-dimensional (2D) material for observing intrinsic ferromagnetic order. However, its relatively low Curie temperature ($T_{\rm C}$) of 45 K severely limits its practical applications, highlighting the need to explore novel metastable polymorphs with enhanced magnetic properties. In this study, we employ a global crystal structure search technique combined with first-principles calculations to systematically investigate new monolayer CrI$_{3}$ phases. Our structural predictions identify two novel polymorphs with Cm and $P2/m$ space groups, both of which are dynamically stable and exhibit significantly higher $T_{\rm C}$ values of 145 K and 81 K, respectively. Electronic property calculations show that the Cm phase is a half-metal, while the $P2/m$ phase is semiconducting with a bandgap of 0.14 eV. Monte Carlo simulations attribute these enhanced $T_{\rm C}$ values to a notable increase in exchange interactions. These findings expand the known phase space of CrI$_{3}$ and provide a promising pathway for designing high-temperature 2D ferromagnets for next-generation spintronic applications.

Key words: chromium triiodide, 2D magnets, structure prediction, first-principles calculations, monolayer structure

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
71.20.-b (Electron density of states and band structure of crystalline solids) 63.20.dk (First-principles theory) 75.50.Pp (Magnetic semiconductors)