Abstract
In partially ordered magnets, order and disorder coexist in the same magnetic phase, distinct from both spin liquids and spin solids. Here, we determine the nature of partial magnetic ordering in the canonical frustrated antiferromagnet Gd2Ti2O7, in which Gd3+ spins occupy a pyrochlore lattice. Using single-crystal neutron-diffraction measurements in applied magnetic field, magnetic symmetry analysis, inelastic neutron-scattering measurements, and spin-wave modeling, we show that its low-temperature magnetic structure involves two propagation vectors (2-k structure) with suppressed ordered magnetic moments and enhanced spin-wave fluctuations. Our experimental results are consistent with theoretical predictions of thermal fluctuation-driven order in Gd2Ti2O7, and reveal that inelastic neutron-scattering measurements on powder samples can solve the longstanding problem of distinguishing single-k and multi-k magnetic structures.
| Original language | English |
|---|---|
| Article number | 99 |
| Journal | npj Quantum Materials |
| Volume | 6 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2021 |
Funding
We are grateful to A.T. Boothroyd, S.T. Bramwell, M.J. Cliffe, M.J.P. Gingras, P. McClarty, M. Mourigal, P.J. Saines, and A.S. Wills for useful discussions, to O. Kirichek and the ISIS Sample Environment Group for cryogenic support, and to J. Makepeace and M.S. Senn for assistance with TOPAS 5. J.A.M.P.’s work was supported by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the US Department of Energy (manuscript preparation). J.A.M.P.’s work at Cambridge (magnetic structure analysis) was supported by Churchill College, University of Cambridge. J.A.M.P., A.B.C., and A.L.G. acknowledge financial support from the STFC, EPSRC (EP/G004528/2), and ERC (Ref: 279705). 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. Work at NHMFL (H.D.Z.) was supported by the NSF-DMR-1157490 and the State of Florida and U.S. Department of Energy. Experiments at the ISIS Neutron and Muon Source were supported by a beam time allocation from the STFC (U.K.). This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
| Funders | Funder number |
|---|---|
| ISIS | DE-AC05-00OR22725 |
| NSF-DMR-1157490 | |
| State of Florida | |
| U.S. Department of Energy | |
| Oak Ridge National Laboratory | |
| H2020 European Research Council | |
| Seventh Framework Programme | 279705 |
| UT-Battelle | |
| Engineering Research Centers | |
| Engineering and Physical Sciences Research Council | EP/G004528/2 |
| Science and Technology Facilities Council | |
| Churchill College, University of Cambridge | |
| European Research Council |