Coexistence of Magnetic Orders in Two-Dimensional Magnet CrI 3

• Published in: Nano letters 2020-01, Vol.20 (1), p.553-558
• Main Authors: Niu, Ben, Su, Tang, Francisco, Brian A, Ghosh, Subhajit, Kargar, Fariborz, Huang, Xiong, Lohmann, Mark, Li, Junxue, Xu, Yadong, Taniguchi, Takashi, Watanabe, Kenji, Wu, Di, Balandin, Alexander, Shi, Jing, Cui, Yong-Tao
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.9b04282

The magnetic properties in two-dimensional van der Waals materials depend sensitively on structure. CrI , as an example, has been recently demonstrated to exhibit distinct magnetic properties depending on the layer thickness and stacking order. Bulk CrI is ferromagnetic (FM) with a Curie temperature of 61 K and a rhombohedral layer stacking, whereas few-layer CrI has a layered antiferromagnetic (AFM) phase with a lower ordering temperature of 45 K and a monoclinic stacking. In this work, we use cryogenic magnetic force microscopy to investigate CrI flakes in the intermediate thickness range (25-200 nm) and find that the two types of magnetic orders, hence the stacking orders, can coexist in the same flake with a layer of ∼13 nm at each surface being in the layered AFM phase similar to few-layer CrI and the rest in the bulk FM phase. The switching of the bulk moment proceeds through a remnant state with nearly compensated magnetic moment along the -axis, indicating formation of -axis domains allowed by a weak interlayer coupling strength in the rhombohedral phase. Our results provide a comprehensive picture on the magnetism in CrI and point to the possibility of engineering magnetic heterostructures within the same material.