posted on 2022-12-28, 15:35authored byShaolong Jiang, Gang Wang, Hanbing Deng, Kai Liu, Qishuo Yang, Erding Zhao, Liang Zhu, Weiteng Guo, Jing Yang, Cheng Zhang, Heshen Wang, Xi Zhang, Jun-Feng Dai, Guangfu Luo, Yue Zhao, Junhao Lin
Two-dimensional (2D) transition metal dihalides (TMDHs)
have been
receiving extensive attention due to their diversified magnetic properties
and promising applications in spintronics. However, controlled growth
of 2D TMDHs remains challenging owing to their extreme sensitivity
to atmospheric moisture. Herein, using a home-built nitrogen-filled
interconnected glovebox system, a universal chemical vapor deposition
synthesis route of high-quality 2D TMDH flakes (1T-FeCl2, FeBr2, VCl2, and VBr2) by reduction
of their trihalide counterparts is developed. Representatively, ultrathin
(∼8.6 nm) FeCl2 flakes are synthesized on SiO2/Si, while on graphene/Cu foil the thickness can be down to
monolayer (1L). Reflective magnetic circular dichroism spectroscopy
shows an interlayer antiferromagnetic ordering of FeCl2 with a Neel temperature at ∼17 K. Scanning tunneling microscopy
and spectroscopy further identify the atomic-scale structures and
band features of 1L and bilayer FeCl2 on graphene/Cu foil.