Transition-Metal Dependent Magnetic Ordering in Intercalated Vanadium Ditelluride

Milo Adams, Judith Clark, Chen Huang, Michael Shatruk

Florida State University Department of Chemistry & Biochemistry
Florida State University Department of Scientific Computing

Vanadium ditelluride is a representative of a larger family of transition metal dichalcogenides, which are known to exhibit a range of unique magnetic and topological properties. To explore how the properties of VTe₂ might be impacted by intercalation of guest species in the van-der-Waals gaps of the layered crystal structure, we have explored compositions M_xVTe₂ (M = Cr, Fe). Plate-like crystals of Fe_0.18VTe and Cr_0.1VTe₂, grown via chemical vapor transport, are air-stable, unlike pure VTe₂ which is readily oxidized when exposed to air. The elemental compositions were confirmed by energy-dispersive X-ray spectroscopy and the trigonal unit cells (space group P-3m1) were established by single crystal x-ray diffraction (SCXRD). Density-functional theory (DFT) calculations on a model structure of Fe_1/4VTe₂ suggest preference for a ferromagnetic state (FM), in which the V and Fe atoms carry magnetic moments of ~1.6 μ_B and ~2.4 μ_B, respectively. In contrast, antiferromagnetic (AFM) ordering is favored for Cr_1/8VTe₂. Experimental magnetic measurements confirm these theoretical predictions. Electronic structure calculations on Fe_1/4VTe₂ and Cr_1/8VTe₂ also reveal flatbands and nodal degeneracies not observed in the band structure of pure VTe₂. The present study suggests that transition metal intercalation of VTe₂ leads to a more stable structure with potentially interesting coupling between electrical and magnetic properties, which we plan to investigate by magnetoresistance measurements.