近日，中国科学院物理研究所王刚团队研究了MnSi₂Te₄：一种具有大负磁电阻的范德华反铁磁半导体。2025年12月22日，《美国化学会志》发表了这一成果。

范德瓦尔斯半导体中的磁性研究为低维磁性的基础探索及高性能二维自旋电子器件的发展提供了重要潜力。

研究组报道了一种新型双八面体过渡金属硫族化合物MnSi₂Te₄的制备、物理性质及第一性原理计算。MnSi₂Te₄具有层状结构并呈现层内异质结特征，其中金属八面体与非金属二聚体八面体交替排列形成锯齿形链。物性表征表明，MnSi₂Te₄是一种共线G型反铁磁半导体，其尼尔温度T_N为18.6 K，并在9 T磁场和100 K条件下表现出高达-42.5%的显著非饱和负磁阻效应。

基于电子能带结构的第一性原理计算揭示，这种强负磁阻主要源于宇称-时间对称性破缺诱导的自旋劈裂。研究组不仅发现了一种具有独特晶体结构和强负磁阻效应的双八面体过渡金属硫族化合物新成员，更为探索下一代自旋电子器件构筑了重要平台。

附：英文原文

Title: MnSi2Te4: A van der Waals Antiferromagnetic Semiconductor with Large Negative Magnetoresistance

Author: Ke Liao, Bo Yin, Yue Pan, Long Chen, Chen Liu, Yan Wu, Seung-Hwan Do, Yifan Gao, Yaling Yang, Yulong Wang, Xuhui Wang, Ying Li, Zhongnan Guo, Junwei Liu, Jiaou Wang, Dong Su, Jie Ma, Quansheng Wu, Gang Wang

Issue&Volume: December 22, 2025

Abstract: Magnetism in van der Waals semiconductors offers significant potential for fundamental research on low-dimensional magnetism and the development of high-performance two-dimensional spintronic devices. Here, we report the growth, physical properties, and first-principles calculations of a new dual-octahedral transition metal chalcogenide (DTMC) MnSi2Te4. MnSi2Te4 features a layered structure with an intralayer heterostructure, where the metal octahedra and nonmetal dimeric octahedra form zigzag chains alternately. Property characterization reveals that MnSi2Te4 is a collinear G-type antiferromagnetic semiconductor, with a Néel temperature TN of 18.6 K and a significant unsaturated negative magnetoresistance (NMR) reaching 42.5% at 9 T and 100 K. First-principles calculations on the electronic band structure demonstrate that the large NMR primarily originates from the spin splitting due to parity-time symmetry breaking. This study not only discovers a new member of DTMCs with a unique crystal structure and large NMR, but also establishes a promising platform for investigating next-generation spintronic devices.

DOI: 10.1021/jacs.5c13595

Source: https://pubs.acs.org/doi/full/10.1021/jacs.5c13595