Physical Vapor Transport Growth of Antiferromagnetic CrCl₃ Flakes Down to Monolayer Thickness

Authors

Jia Wang, University of Nebraska-LincolnFollow
Zahra Ahmadi, University of Nebraska-LincolnFollow
David Lujan, University of Texas at Austin
Jeongheon Choe, University of Texas at Austin
Xiaoqin Li, University of Texas at Austin
Jeffrey E. Shield, University of Nebraska - LincolnFollow
Xia Hong, University of Nebraska-LincolnFollow

Date of this Version

8-12-2022

Citation

arXiv:2208.06298 12 August 2022

Abstract

The van der Waals magnets CrX₃ (X = I, Br, and Cl) exhibit highly tunable magnetic properties and are promising candidates for developing novel two-dimensional (2D) magnetic devices such as magnetic tunnel junctions and spin tunneling transistors. Previous studies of CrCl₃ have mainly focused on mechanically exfoliated samples. Controlled synthesis of high quality atomically thin flakes is critical for their technological implementation but has not been achieved to date. Here, we report the growth of large CrCl3 flakes with well-defined facets down to monolayer thickness (~0.6 nm) via the physical vapor transport technique. Long stripes of tri-layer samples with length exceeding 60 μm have been obtained. High-resolution transmission electron microscopy studies show that the CrCl₃ flakes are single crystalline in the monoclinic structure, consistent with the Raman results. The thick CrCl3 samples are stable at room temperature for about 5 months, while monolayer flakes show signs of degradation in 6 days. The tunneling magnetoresistance of graphite/CrCl3/graphite tunnel junctions confirms that few-layer CrCl3 possesses in-plane magnetic anisotropy and Néel temperature of 17 K. Our study paves the path for developing CrCl₃-based scalable 2D spintronic applications.