サブレイヤー化学により半導体・磁性ランタノイドMXeneを実現（Sublayer Chemistry Enables Semiconducting and Magnetic Lanthanide MXenes）

2026-07-30 中国科学院（CAS）

Synthesis process of lanthanide MXenes (Image by NIMTE)

＜関連情報＞

• https://english.cas.cn/newsroom/research-news/202607/t20260730_1183456.shtml
• https://www.nature.com/articles/s41586-026-10802-2

層間挿入ハロゲン化物から得られる半導体および磁性ランタニドMXene Semiconducting and magnetic lanthanide MXenes from intercalated halides

Qian Fang,Liming Wang,Kai Chang,Hongxin Yang,Pu Yan,Kecheng Cao,Mian Li,Jianming Xue,Xiaoping Ouyang,Zhifang Chai & Qing Huang
Nature  Published:22 July 2026
DOI:https://doi.org/10.1038/s41586-026-10802-2

Abstract

Two-dimensional (2D) magnetic semiconductors are crucial for next-generation information storage and spintronic technologies^1,2. MXenes, owing to compositional diversity and tunable properties, provide a platform for designing functional materials^3,4,5. Incorporating lanthanides (Ln) introduces localized 4f electrons with strong spin polarization, while potentially enabling semiconducting behaviour, offering a viable route to magnetic semiconductors^6,7. However, the scarcity of MAX precursors and the susceptibility of Ln to dissolution in common etchants (for example, HF), compared with other M elements such as Mo, hinder the synthesis of lanthanide MXenes (Ln₂CT₂) by conventional ‘top-down’ etching⁸. Here we propose a general ‘bottom-up’ methodology for synthesizing Ln₂CT₂ (Ln = Gd, Tb, Dy, Ho, Er, Lu; T = Cl, Br) using layered halides as van der Waals building blocks. Multilayer Ln₂CT₂ exhibits composition-tunable properties, characterized by optical absorption onsets spanning 1.26–1.71 eV, room-temperature resistivity of 0.329–36.1 Ω cm with a negative temperature coefficient, and low-temperature ferromagnetic hysteresis at 2 K accompanied by positive Curie–Weiss temperatures between 6 K and 59 K. Theoretical calculations show that the d-electron states around the Fermi level (E_f) are largely diminished in bare Ln₂C, whereas surface terminals further exhaust these states to open band gaps. Meanwhile, the highly localized 4f electrons in Ln₂CT₂, located far from the E_f, contribute to the spin splitting for the observed ferromagnetic behaviour. This combination of semiconducting and magnetic properties makes Ln₂CT₂ a valuable candidate for spintronic device applications.