- By:
- Parker, David S; Yin, Li ; Samolyuk, German D; Liurukara, Duminda S; Wang, Xiaoping ; Cooper, Valentino R; Liu, Yaohua ; Bud’ko, Sergey; Sefat, Athena S
- Journal Name:
- Physical Review B
- Page Number:
- 174414
- Volume:
- 105
- Issue Number:
- 17
- Publication Date:
- December 27, 2023
- View DOI Listing:
- https://doi.org/10.1103/PhysRevB.105.174414
Abstract
We report a detailed theoretical and experimental study on the vanadium monotelluride VTe, which crystallizes in the NiAs hexagonal structure. First-principles calculations reveal a complex hierarchy of magnetic interactions and energy scales, with the ground state theoretically determined as an (12, 0, 12) antiferromagnetic ordering with insulating character and a band gap of 0.5 eV. Experimental synthesis and characterization efforts find a substantially off-stoichiometric orthorhombic structure (a defect NiAs structure) with composition V0.85Te, and an apparent Néel point of some 45 K. First-principles calculations find good agreement with the observed Néel point. We also give an extended examination of the effects of off-stoichiometry on the calculated energetics, finding significant volume-related effects. Our first-principles calculations find the stoichiometric phase VTe to have a negative vanadium defect formation energy of over 1 eV, thus explaining the formation of the off-stoichiometric phase. Finally, we provide a structural explanation for the formation of defect structures in this and numerous other NiAs-structure materials.
