Abstract
The kagome metals display an intriguing variety of electronic and magnetic phases arising from the connectivity of atoms on a kagome lattice. A growing number of these materials with vanadium-kagome nets host charge-density waves (CDWs) at low temperatures, including ScV6Sn6, CsV3Sb5, and V3Sb2. Curiously, only the Sc version of the RV6Sn6 materials with a HfFe6Ge6-type structure hosts a CDW (R = Gd-Lu, Y, Sc). In this study, we investigate the role of rare earth size in CDW formation in the RV6Sn6 compounds. Magnetization measurements on our single crystals of (Sc,Lu)V6Sn6 and (Sc,Y)V6Sn6 establish that the CDW is suppressed by substituting Sc by larger Lu or Y. Single-crystal X-ray diffraction reveals that compressible Sn-Sn bonds accommodate the larger rare earth atoms within loosely packed R-Sn-Sn chains without significantly expanding the lattice. We propose that Sc provides extra room in these chains crucial to CDW formation in ScV6Sn6. Our rattling chain model explains why both physical pressure and substitution by larger rare earth atoms hinder CDW formation despite opposite impacts on lattice size. We emphasize the cooperative effect of pressure and rare earth size by demonstrating that pressure further suppresses the CDW in a Lu-doped ScV6Sn6 crystal. Our model not only addresses why a CDW only forms in the RV6Sn6 materials with tiny Sc but also advances our understanding of why unusual CDWs form in the kagome metals.
| Original language | English |
|---|---|
| Pages (from-to) | 20943-20950 |
| Number of pages | 8 |
| Journal | Journal of the American Chemical Society |
| Volume | 145 |
| Issue number | 38 |
| DOIs | |
| State | Published - Sep 27 2023 |
Funding
We thank Bryan C. Chakoumakos of the Oak Ridge National Laboratory for his helpful discussions with the single-crystal X-ray refinements and Adam Malin for creating cover art for this paper. M.A.M. and D.M. acknowledge support from the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences, and Engineering Division. W.R.M., H.W.S.A., C.L.A., and J.D. acknowledge support from the Gordon and Betty Moore Foundation’s EPiQS Initiative, Grant GBMF9069 to D.M. S.M. and R.P.M. acknowledge the support from AFOSR MURI (Novel Light-Matter Interactions in Topologically Non-Trivial Weyl Semimetal Structures and Systems) grant# FA9550-20-1-0322. M.M. and H.B.C. were supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Early Career Research Program Award KC0402020, under Contract DE-AC05-00OR22725. 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. A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-2128556 and the State of Florida. We thank Bryan C. Chakoumakos of the Oak Ridge National Laboratory for his helpful discussions with the single-crystal X-ray refinements and Adam Malin for creating cover art for this paper. M.A.M. and D.M. acknowledge support from the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences, and Engineering Division. W.R.M., H.W.S.A., C.L.A., and J.D. acknowledge support from the Gordon and Betty Moore Foundation’s EPiQS Initiative, Grant GBMF9069 to D.M. S.M. and R.P.M. acknowledge the support from AFOSR MURI (Novel Light–Matter Interactions in Topologically Non-Trivial Weyl Semimetal Structures and Systems) grant# FA9550-20-1-0322. M.M. and H.B.C. were supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Early Career Research Program Award KC0402020, under Contract DE-AC05-00OR22725. 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. A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-2128556 and the State of Florida.
