From Stoner to local moment magnetism in atomically thin Cr2Te3

Yong Zhong; Cheng Peng; Haili Huang; Dandan Guan; Jinwoong Hwang; Kuan H Hsu; Yi Hu; Chunjing Jia; Brian Moritz; Donghui Lu; Jun-Sik Lee; Jin-Feng Jia; Thomas P Devereaux; Sung-Kwan Mo; Zhi-Xun Shen

doi:10.1038/s41467-023-40997-1

From Stoner to local moment magnetism in atomically thin Cr₂Te₃

Nat Commun. 2023 Sep 2;14(1):5340. doi: 10.1038/s41467-023-40997-1.

Authors

Yong Zhong^#^{1

2

3}, Cheng Peng^#⁴, Haili Huang^#⁵, Dandan Guan^{6

7

8}, Jinwoong Hwang^{9

4

10}, Kuan H Hsu¹¹, Yi Hu¹¹, Chunjing Jia^{4

12}, Brian Moritz⁴, Donghui Lu¹³, Jun-Sik Lee¹³, Jin-Feng Jia⁵, Thomas P Devereaux^{4

11}, Sung-Kwan Mo¹⁴, Zhi-Xun Shen^{15

16

17}

Affiliations

¹ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. ylzhong@stanford.edu.
² Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA. ylzhong@stanford.edu.
³ Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA. ylzhong@stanford.edu.
⁴ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
⁵ Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, School of Physics and Astronomy, Shanghai Jiao Tong University, 200240, Shanghai, China.
⁶ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA. ddguan@sjtu.edu.cn.
⁷ Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA. ddguan@sjtu.edu.cn.
⁸ Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, School of Physics and Astronomy, Shanghai Jiao Tong University, 200240, Shanghai, China. ddguan@sjtu.edu.cn.
⁹ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
¹⁰ Department of Physics and Institute of Quantum Convergence Technology, Kangwon National University, Chucheon, 24341, Republic of Korea.
¹¹ Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.
¹² Department of Physics, University of Florida, Gainesville, FL, 32611, USA.
¹³ Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
¹⁴ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. skmo@lbl.gov.
¹⁵ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA. zxshen@stanford.edu.
¹⁶ Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA. zxshen@stanford.edu.
¹⁷ Department of Physics, Stanford University, Stanford, CA, 94305, USA. zxshen@stanford.edu.

^# Contributed equally.

Abstract

The field of two-dimensional (2D) ferromagnetism has been proliferating over the past few years, with ongoing interests in basic science and potential applications in spintronic technology. However, a high-resolution spectroscopic study of the 2D ferromagnet is still lacking due to the small size and air sensitivity of the exfoliated nanoflakes. Here, we report a thickness-dependent ferromagnetism in epitaxially grown Cr₂Te₃ thin films and investigate the evolution of the underlying electronic structure by synergistic angle-resolved photoemission spectroscopy, scanning tunneling microscopy, x-ray absorption spectroscopy, and first-principle calculations. A conspicuous ferromagnetic transition from Stoner to Heisenberg-type is directly observed in the atomically thin limit, indicating that dimensionality is a powerful tuning knob to manipulate the novel properties of 2D magnetism. Monolayer Cr₂Te₃ retains robust ferromagnetism, but with a suppressed Curie temperature, due to the drastic drop in the density of states near the Fermi level. Our results establish atomically thin Cr₂Te₃ as an excellent platform to explore the dual nature of localized and itinerant ferromagnetism in 2D magnets.

Grants and funding

DE-AC02-05CH11231/U.S. Department of Energy (DOE)