Tustain, Katherine and Ward-O’Brien, Brendan and Bert, Fabrice and Han, Tianheng and Luetkens, Hubertus and Lancaster, Tom and Huddart, Benjamin M. and Baker, Peter J. and Clark, Lucy (2020) 'From magnetic order to quantum disorder in the Zn-barlowite series of S = 1/2 kagomé antiferromagnets.', npj Quantum materials., 5 (1). p. 74.
We report a comprehensive muon spectroscopy study of the Zn-barlowite series of S=12 kagomé antiferromagnets, ZnxCu4−x(OH)6FBr, for x = 0.00 to 0.99(1). By combining muon spin relaxation and rotation measurements with state-of-the-art density-functional theory muon-site calculations, we observe the formation of both μ–F and μ–OH complexes in Zn-barlowite. From these stopping sites, implanted muon spins reveal the suppression of long-range magnetic order into a possible quantum spin liquid state upon the increasing concentration of Zn-substitution. In the parent compound (x = 0), static long-range magnetic order below TN = 15 K manifests itself in the form of spontaneous oscillations in the time-dependent muon asymmetry signal consistent with the dipolar fields expected from the calculated muon stopping sites and the previously determined magnetic structure of barlowite. Meanwhile, in the x = 1.0 end-member of the series—in which antiferromagnetic kagomé layers of Cu2+S=12 moments are decoupled by diamagnetic Zn2+ ions—we observe that dynamic magnetic moment fluctuations persist down to at least 50 mK, indicative of a quantum disordered ground state. We demonstrate that this crossover from a static to dynamic magnetic ground state occurs for compositions of Zn-barlowite with x > 0.5, which bears resemblance to the dynamical behaviour of the widely studied Zn-paratacamite series that contains the quantum spin liquid candidate herbertsmithite.
|Full text:||(VoR) Version of Record|
Available under License - Creative Commons Attribution.
Download PDF (1635Kb)
|Publisher Web site:||https://doi.org/10.1038/s41535-020-00276-4|
|Publisher statement:||This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.|
|Date accepted:||22 September 2020|
|Date deposited:||29 October 2020|
|Date of first online publication:||23 October 2020|
|Date first made open access:||29 October 2020|
Save or Share this output
|Look up in GoogleScholar|