Room-temperature intrinsic ferromagnetism in epitaxial CrTe2 ultrathin films

DOI: 10.1038/s41467-021-22777-x

Authors: Xiaoqian Zhang (Nanjing University; University of Missouri) , Qiangsheng Lu (University of Missouri) , Wenqing Liu (Nanjing University; Royal Holloway University of London) , Wei Niu (Nanjing University of Posts and Telecommunications) , Jiabao Sun (Royal Holloway University of London) , Jacob Cook (University of Missouri) , Mitchel Vaninger (University of Missouri) , Paul F. Miceli (University of Missouri) , David J. Singh (University of Missouri) , Shang-Wei Lian (National Cheng Kung University) , Tay-Rong Chang (National Cheng Kung University; Center for Quantum Frontiers of Research and Technology (QFort)) , Xiaoqing He (University of Missouri) , Jun Du (Nanjing University) , Liang He (Nanjing University) , Rong Zhang (Nanjing University) , Guang Bian (University of Missouri) , Yongbing Xu (Nanjing University; The University of York)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 12

State: Published (Approved)
Published: May 2021
Diamond Proposal Number(s): 22532

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 μ B /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.

Journal Keywords: Magnetic properties and materials; Two-dimensional materials

Diamond Keywords: Spintronics; Ferromagnetism

Subject Areas: Materials, Physics


Instruments: I10-Beamline for Advanced Dichroism

Added On: 10/05/2021 13:18

Documents:
s41467-021-22777-x.pdf

Discipline Tags:

Materials Science Quantum Materials Physics Electronics Hard condensed matter - electronic properties Magnetism Surfaces interfaces and thin films

Technical Tags:

Spectroscopy Circular Dichroism (CD) X-ray Absorption Spectroscopy (XAS) X-ray Magnetic Circular Dichroism (XMCD)