Abstract
While the discovery of two-dimensional (2D) magnets opens the door for fundamental physics and next-generation spintronics, it is technically challenging to achieve the room-temperature ferromagnetic (FM) order in a way compatible with potential device applications. Here, we report the growth and properties of single- and few-layer CrTe2, a van der Waals (vdW) material, on bilayer graphene by molecular beam epitaxy (MBE). Intrinsic ferromagnetism with a Curie temperature (TC) up to 300 K, an atomic magnetic moment of ~0.21 μB/Cr and perpendicular magnetic anisotropy (PMA) constant (Ku) of 4.89 × 105 erg/cm3 at room temperature in these few-monolayer films have been unambiguously evidenced by superconducting quantum interference device and X-ray magnetic circular dichroism. This intrinsic ferromagnetism has also been identified by the splitting of majority and minority band dispersions with ~0.2 eV at Г point using angle-resolved photoemission spectroscopy. The FM order is preserved with the film thickness down to a monolayer (TC ~ 200 K), benefiting from the strong PMA and weak interlayer coupling. The successful MBE growth of 2D FM CrTe2 films with room-temperature ferromagnetism opens a new avenue for developing large-scale 2D magnet-based spintronics devices.
| Original language | English |
|---|---|
| Article number | 2492 |
| Journal | Nature Communications |
| Volume | 12 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 1 2021 |
| Externally published | Yes |
Funding
This work is supported by the National Key Research and Development Program of China (No. 2016YFA0300803, No. 2017YFA0206304), the National Basic Research Program of China (No. 2014CB921101), the National Natural Science Foundation of China (No. 61427812, 11774160, 11574137, 61474061, 61674079, 11904174), Jiangsu Shuangchuang Program, the Natural Science Foundation of Jiangsu Province of China (No. BK20140054, BK20190729), NUPTSF (Grant No. NY219024), the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (19KJB510047), UK EPSRC (EP/S010246/1), leverhulme Trust (LTSRF1819 ), and Royal Society (IEC NSFC81680). G.B. is supported by the US National Science Foundation (NSF-DMR#1809160). Work of David Singh is supported by the U.S. Department of Energy, Basic Energy Sciences, Award Number DE-SC0019114. Diamond Light Source is acknowledged to I10 under proposal MM22532. T.-R.C. is supported by the Young Scholar Fellowship Program from the Ministry of Science and Technology (MOST) in Taiwan, under a MOST grant for the Columbus Program MOST108-2636-M-006-002, National Cheng Kung University, Taiwan, and National Center for Theoretical Sciences, Taiwan. This work is also partially supported by the MOST, Taiwan, Grant MOST107-2627-E-006-001 and by Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at National Cheng Kung University (NCKU).