Vacancy-Induced Ferromagnetism of MoS2 Nanosheets

• Published in: Journal of the American Chemical Society 2015-02, Vol.137 (7), p.2622-2627
• Main Authors: Cai, Liang, He, Jingfu, Liu, Qinghua, Yao, Tao, Chen, Lin, Yan, Wensheng, Hu, Fengchun, Jiang, Yong, Zhao, Yidong, Hu, Tiandou, Sun, Zhihu, Wei, Shiqiang
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja5120908

Outstanding magnetic properties are highly desired for two-dimensional ultrathin semiconductor nanosheets. Here, we propose a phase incorporation strategy to induce robust room-temperature ferromagnetism in a nonmagnetic MoS2 semiconductor. A two-step hydrothermal method was used to intentionally introduce sulfur vacancies in a 2H-MoS2 ultrathin nanosheet host, which prompts the transformation of the surrounding 2H-MoS2 local lattice into a trigonal (1T-MoS2) phase. 25% 1T-MoS2 phase incorporation in 2H-MoS2 nanosheets can enhance the electron carrier concentration by an order, introduce a Mo4+ 4d energy state within the bandgap, and create a robust intrinsic ferromagnetic response of 0.25 μB/Mo by the exchange interactions between sulfur vacancy and the Mo4+ 4d bandgap state at room temperature. This design opens up new possibility for effective manipulation of exchange interactions in two-dimensional nanostructures.