Ge Jun, Luo Tianchuang, Lin Zuzhang, Shi Jianping, Liu Yanzhao, Wang Pinyuan, Zhang Yanfeng, Duan Wenhui, Wang Jian
International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, China.
Adv Mater. 2021 Jan;33(4):e2005465. doi: 10.1002/adma.202005465. Epub 2020 Dec 11.
2D magnetism plays a key role in both fundamental physics and potential device applications. However, the instability of the discovered 2D magnetic materials has been one main obstacle in deep research and potential application of 2D magnetism. Here, a localized magnetic moment induced by Pt vacancies in air-stable type-II Dirac semimetal PtSe flakes is reported. The localized magnetic moments give rise to the Kondo effect, evidenced by logarithmic increment of resistance with decreasing temperature and isotropic negative longitudinal magnetoresistance. Additionally, the induced magnetic moment and Kondo temperature appear to depend on thickness in the thinner samples (<10 nm). The small magnetocrystalline anisotropy revealed by first-principles calculation indicates that the magnetic moments are randomly localized instead of long-range ordered. The findings demonstrate a new means to induce magnetism in 2D non-magnetic materials.
二维磁性在基础物理学和潜在的器件应用中都起着关键作用。然而，已发现的二维磁性材料的不稳定性一直是二维磁性深入研究和潜在应用的一个主要障碍。在此，报道了在空气稳定的II型狄拉克半金属PtSe薄片中由铂空位诱导产生的局域磁矩。这些局域磁矩引发了近藤效应，其证据是电阻随温度降低呈对数增加以及各向同性的负纵向磁阻。此外，在较薄的样品（<10纳米）中，诱导磁矩和近藤温度似乎取决于厚度。第一性原理计算揭示的小磁晶各向异性表明，磁矩是随机局域化的，而非长程有序的。这些发现展示了一种在二维非磁性材料中诱导磁性的新方法。
