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.
| Original language | English |
|---|---|
| Article number | 174414 |
| Journal | Physical Review B |
| Volume | 105 |
| Issue number | 17 |
| DOIs | |
| State | Published - May 1 2022 |
Funding
This work was supported by the U.S. Department of Energy, Basic Energy Sciences, Materials Science and Engineering Division. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. G.D.S. (LMTO first principles calculations) was supported by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory. Work at Ames Laboratory (S.B.) was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-AC02-07CH11358. This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. This manuscript has been authored by employees of UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes.
| Funders | Funder number |
|---|---|
| CADES | DE-AC05-00OR22725 |
| Data Environment for Science | |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| Ames Laboratory | |
| Division of Materials Sciences and Engineering | DE-AC02-07CH11358 |