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arXiv · 2011.02775

Engineering the ligand states by surface functionalization: A new way to enhance the ferromagnetism of CrI3

Hongxing Li·Zi-Peng Cheng·Bin-Guang He·Wei-Bing Zhang
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Abstract

The newly discovered 2D magnetic materials provide new opportunities for basic physics and device applications. However, their low Curie temperature (TC) is a common weakness. In this paper, by combining magnetic Hamiltonian, Wannier functions and first-principle calculations, we systematically study the magnetic properties of monolayer CrI3 functionalized by halogen. The magnetic exchange coupling (EX) and magnetic anisotropy (MA) are found to increase significantly by X (X=F, Cl and Br) atom adsorption, and increase along with the coverage of X atom. In the frame work of superexchange theory, the enhanced EX can be ascribed to the reduced energy difference and increased hopping strength between Cr d and I p orbitals, due to the states of I ligand are engineered by X adatom. Besides, the X adatom may provide additional ferromagnetic superexchange channel. Finally, the CrI3 that one side is fully adsorbed by F atoms is found to be a room temperature ferromagnetic semiconductor with TC=650 K. Our results not only give an insightful understanding for the enhancement of ferromagnetism of CrI3 by atom adsorption, but also propose a promising way to improve the ferromagnetism of 2D magnetic materials.

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Hongxing Li, Zi-Peng Cheng, Bin-Guang He, Wei-Bing Zhang. 2020-11-05. Engineering the ligand states by surface functionalization: A new way to enhance the ferromagnetism of CrI3. https://arxiv.org/abs/2011.02775

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