Strain-induced magnetic phase transition and antiferromagnetic skyrmions of Re atoms adsorbed on a Janus MoSSe monolayer

The realization of magnetic skyrmions in nanomaterials offers significant potential for both fundamental research and practical applications. Unfortunately, while Janus structures offer a promising approach for achieving a Dzyaloshinskii-Moriya interaction (DMI) in two-dimensional (2D) materials, the relatively small DMI in these systems poses challenges for the effective induction of skyrmions. In this paper, we explore the magnetic properties of $5d$ transition metal atoms adsorption on a Janus MoSSe monolayer ($5d$-TM@MoSSe) through first-principles calculations. In particular, the positive exchange coefficient ($J$), large DMI(${d}_{\ensuremath{\parallel}}$), and perpendicular magnetic anisotropy (PMA) energy of 7.35 meV in Re@MoSSe are superior to those observed in the TM@MoSSe systems. Applying biaxial tensile strain can significantly enhance these parameters while also reversing the magnetic state and the chiral of ${d}_{\ensuremath{\parallel}}$ in Re@MoSSe. At 8% tensile strain, ${d}_{\ensuremath{\parallel}}$ reaches its maximum value of 4.324 meV; this is because the change of $d$ orbital distribution around Fermi level induced by tensile strain plays a key role in determining a DMI. The value is more than 60 times larger than that of zero strain and is superior to that of state-of-the-art heavy metal/ferromagnetic heterostructures. Furthermore, micromagnetic simulations reveal that antiferromagnetic (AFM) skyrmions in the Re@MoSSe monolayer under 8% tensile strain is highly stable, independent of external stray fields. These findings provide valuable insights into the study of AFM skyrmions and the DMI in 2D materials.