Vacancy-induced suppression of charge density wave order and its impact on magnetic order in kagome antiferromagnet FeGe
Year: 2025
Type: article
Abstract: Two-dimensional (2D) kagome lattice metals are interesting because their corner sharing triangle structure enables a wide array of electronic and magnetic phenomena. Recently, post-growth annealing is shown to both suppress charge density wave (CDW) order and establish long-range CDW with the ability to cycle between states repeatedly in the kagome antiferromagnet FeGe. Here we perform transport, neutron scattering, scanning transmission electron microscopy (STEM), and muon spin rotation (μSR) experiments to unveil the microscopic mechanism of the annealing process and its impact on magneto-transport, CDW, and magnetism in FeGe. Annealing at 560 °C creates uniformly distributed Ge vacancies, preventing the formation of Ge-Ge dimers and thus CDW, while 320 °C annealing concentrates vacancies into stoichiometric FeGe regions with long-range CDW. The presence of CDW order greatly affects the anomalous Hall effect, incommensurate magnetic order, and spin-lattice coupling in FeGe, placing FeGe as the only kagome lattice material with tunable CDW and magnetic order. FeGe is an antiferromagnetic kagome metal with a rich magnetic and electronic phase diagram. Recently it was found that post-growth annealing of FeGe can suppress or induce charge density wave order depending on the annealing temperature. Here, Klemm, Siddique et al show the critical role that annealing induced Ge-vacancies and stacking faults play in the formation of charge density wave order in FeGe.
Source: Nature Communications
Authors: Mason L. Klemm, Saif Siddique, Yuan-Chun Chang, Sijie Xu, Yaofeng Xie, Tanner Legvold, Mehrdad T. Kiani, Xiaokun Teng, Bin Gao, Feng Ye, Huibo Cao, Yiqing Hao, Wei Tian, Hubertus Luetkens, Masaaki Matsuda, Douglas Natelson, Zurab Guguchia, Chien-Lung Huang, Ming Yi, Judy J. Cha, Pengcheng Dai
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, National Cheng Kung University, National Science and Technology Council, Office of Science, Cornell Center for Materials Research, Kavli Institute at Cornell, Cornell University, Division of Materials Research, Oak Ridge National Laboratory
Awards: G121915436, G1645119126, MRI: Acquisition of a Cryogenic, Aberration-Corrected Scanning Transmission Electron Microscope for Advanced Materials Research and Education, G203625172, G2411683797, G2414013413, G2988778103, Ming Yi Experimental Investigator Award, G3794648935, G3945850812, G4226411685, G4303070870, G4423657506, G453019600, G4919857398, G5046801523, G5518237547, Neutron scattering studies of magnetic order and spin dynamics in two-dimensional magnetic materials, G675320460, Unconventional correlated quantum phases of layered materials, DECIPHERING AND MANIPULATING LOW DIMENSIONAL MAGNETISM, Angular momentum transport in insulators: Magnons and other emergent excitations, G799213039, MIP: Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM), DECIPHERING AND MANIPULATING LOW DIMENSIONAL MAGNETISM, G8140262571, G8269158468, G8906985441, G991067456
OpenAlex ID: W4409219426