Magnetic properties manipulation of CrTe2 bilayer through strain and self-intercalation

Abstract

Two-dimensional van der Waals magnetic crystals have been attracting significant research interest in recent years, and the manipulation of their magnetism is important for understanding their physical property and achieving their actual applications. Here, we systematically studied the manipulation of magnetic properties of a CrTe₂ bilayer through in-plane strain and self-intercalation. We found that the magnetic ground state of the CrTe₂ bilayer varies from intralayer antiferromagnetic coupling to ferromagnetic coupling and then to interlayer antiferromagnetic coupling when the strain changes from −6% to 4%, which should result from the coupling between intralayer Cr atoms tuned from direct Cr–Cr exchange to indirect Cr–Te–Cr superexchange. The magnetic easy axis of the CrTe₂ bilayer varies from the in-plane to the out-of-plane owing to the change of p_z orbital occupation from Te atoms near the Fermi level. Moreover, the magnetic ground states of different Cr-intercalated concentrations for the CrTe₂ bilayer are all ferromagnetic, and the magnetic easy axis is in-plane, which are different from the intrinsic one. Our results indicate that the magnetic property of the CrTe₂ bilayer is sensitive to the in-plane strain and self-intercalation, which provides important guidance for the further magnetic manipulation of the CrTe₂ bilayer in theoretical research and application of magnetic strain sensors and spin transistors.