Strain modulation of magnetic coupling in the metallic van der waals magnet Fe3GeTe2

Abstract

We investigated the strain modulation of the magnetic states and interatomic exchange interactions in layered van der Waals magnet Fe3GeTe2 by detailed first-principles studies. The energy-minimum calculations demonstrate the ground state of bulk Fe3GeTe2 is weak antiferromagnetic coupling, in contrast to most precious reports, and it can be modulated to ferromagnetic coupling under small a-axis distortion (~2%). More importantly, we obtained the variation of exchange coupling parameters Jij and Curie temperature TC under both uniaxial and isotropic strain, and found the TC can be enhanced to room temperature in the case of uniaxial lattice distortion, especially along the a-axis. Our work clarified the role of intra- and inter-layer magnetic coupling in tuning of the ground state magnetism that can be generally applied in two-dimensional layered materials and suggested a paradigm for tuning TC with uniaxial strain in Fe3GeTe2.