Free-standing 2D non-van der Waals antiferromagnetic hexagonal FeSe semiconductor: halide-assisted chemical synthesis and Fe2+ related magnetic transitions

作者：Xu, Junjie; Li, Wei; Zhang, Biao; Zha, Liang; Hao, Wei; Hu, Shixin; Yang, Jinbo; Li, ShuZhou; Gao, Song; Hou, Yanglong^*

来源：Chemical Science, 2021, 13(1): 203-209.

DOI：10.1039/d1sc04122c

• NANOSHEETS
• DESIGN
• NANOCRYSTALS

The scarcity of two-dimensional (2D) magnetic nanostructures has hindered their applications in spintronics, which is attributed to that most magnetic materials exhibit non-van der Waals (nvdWs) structures and it is hard to reduce their thickness to 2D nanostructures. Thus it is necessary to develop a promising strategy for free-standing 2D magnetic nvdWs nanostructures. We have achieved free-standing 2D nvdWs hexagonal FeSe with a thickness of 2.9 nm by the reaction between the oleylamine-Se complex and Fe2+ with the assistance of Cl-, where the synergetic effects of Cl- and -NH2 lead to anisotropic growth. Inspiringly, the 2D hexagonal FeSe exhibits intrinsic antiferromagnetic order rooted in Fe2+ and semiconducting nature. In addition, the temperature variation would result in the chemical environment changes of Fe2+, responsible for the temperature-dependent magnetic transitions. This work promotes the potential applications of 2D hexagonal FeSe and the preparation of other 2D nvdWs materials.

• 单位
  兰州大学; 北京大学; 南阳理工学院