Investigating Structural and Magnetic Properties of Low-Dimensional Fe_xNbSe₂

Magnetically intercalated 2D transition metal dichalcogenides (TMDs) represent a promising class of low-dimensional magnetic materials for ultralow-power applications based on the manipulation of electron spin. The ability to tune the magnetic properties based on the choice of intercalant and host lattice offers a versatile platform for designing novel 2D magnets that would be difficult to access from their bulk counterparts, yet the phase space afforded by this approach remains largely unexplored. Here, we study the chemical intercalation of Fe²⁺ ions into few-layer 2<i>H</i>-NbSe₂ to engineer long-range antiferromagnetic order approaching the 2D limit. Utilizing Raman spectroscopy, we investigate the structural changes between NbSe₂ and Fe_xNbSe₂ and track the phonon modes accompanied by Fe²⁺ intercalation to gauge the extent and homogeneity of intercalant ordering. Additionally, we monitor the effects of thermal annealing at various temperatures on the intercalation amount and degree of ordering in the material to potentially find an onset temperature for leveraging the intercalation process. Furthermore, we characterize the magnetic behavior of the system via variable-temperature magnetotransport measurements. We anticipate our results to be relevant in understanding the intercalation of related transition metal intercalated TMD systems and aid in the scalability and development of 2D heterostructures for use in next generation low-power electronic and spintronic devices.