Modifying the Dzyaloshinskii-Moriya Interaction via Disruption of Ordered Intercalation in a van der Waals Magnet

The intercalation of magnetic atoms into van der Waals (vdW) gaps offers a unique opportunity to manipulate the Dzyaloshinskii-Moriya interaction (DMI) and magnetic structures by modifying the local atomic structures in vdW magnets. Herein, a new strategy is proposed for modifying DMI by disrupting the atomic-scale order within the Cr sublattice of Cr-intercalated 2H-TaS₂, i.e., Cr_1/3TaS₂, which enables significant and efficient DMI modulation across a wide range by controlling the degree of atomic disorder. Lorentz transmission electron microscopy reveals pronounced variations in spin-helix periods, which are correlated with changes in the degree of Cr ordering within the vdW gaps, as shown by atomic-resolution imaging and principal component analysis. First-principles calculations confirm that this structural ordering affects the DMI strength, thereby notably altering the spin textures and magnetic transition behaviors. These findings are further supported by macroscopic magnetic measurements and micromagnetic simulations, highlighting new pathways for controlling magnetic properties of vdW materials.