Intercalation-Dependent Magnetism in Fe-Intercalated Tantalum Disulfide

Filling the van der Waals gap by self- or foreign atoms in 2D materials has been proven of great interest because a spectrum of quantum mechanical properties can be tuned. Particularly, Fe-intercalated FexTaS2 crystals show relatively high Curie temperature (TC), air-stable, and giant magnetoresistance. However, the underlying Fe-intercalant concentration- and arrangement-dependent magnetic properties remain elusive, largely impeding the precise design of multifunctional FexTaS2 crystals with desired functionalities. Here, we employ aberration-corrected scanning transmission electron microscopy (STEM) and density functional theory (DFT) to systematically explore the Fe-intercalation arrangement and relative magnetic properties in a series of Fe-intercalated FexTaS2 crystals. We found that the Fe intercalations evolve from 2a × 2a to disorder and then to √3a × √3a arrangements with increasing intercalation concentration, displaying consistent occupancy of the octahedral vacancies. The TC and coercivity (Hc) strongly depend on the Fe-intercalation arrangements and are weakly coupled with the Fe concentrations. DFT calculations suggest that these phenomena originate from the modified spin-polarized states and magnetic anisotropy, being strongly dependent on the Fe-intercalation arrangements. This work sheds light on the origin of arrangement- and concentration-dependent magnetism in foreign-intercalated 2D magnetic systems, paving the way for precise tuning of magnetic orders by controlled foreign intercalation.