μSR studies of the kagomé antiferromagnet (H3O)Fe3(OH)6(SO4)2
| Autor: | B. Nachumi, Y. Fudamato, Andrew Harrison, Yasutomo J. Uemura, K. M. Kojima, James S. Lord, D. Visser, Andrew S. Wills, M. I. Larkin, Graeme Luke |
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| Rok vydání: | 2000 |
| Předmět: |
Physics
Muon Hydronium Condensed matter physics Magnetism Degenerate energy levels Condensed Matter Physics Electronic Optical and Magnetic Materials Ion chemistry.chemical_compound chemistry Lattice (order) Antiferromagnetism Condensed Matter::Strongly Correlated Electrons Electrical and Electronic Engineering Ground state |
| Zdroj: | Physica B: Condensed Matter. :217-220 |
| ISSN: | 0921-4526 |
| DOI: | 10.1016/s0921-4526(00)00371-9 |
| Popis: | The Heisenberg kagome antiferromagnet is a frustrated system that provides a simple model for the study of strongly fluctuating magnets with a highly degenerate ground state. Hydronium jarosite, (H3O)Fe3(OH)6(SO4)2 possesses a kagome lattice of Fe3+ ions that behave as S= 5 2 Heisenberg moments coupled through strong antiferromagnetic exchange. DC susceptibility measurements reveal a spin-glass-like transition at Tf≅15 K. We have performed muon-spin relaxation (μSR) measurements on this material to elucidate the nature of this transition. Well above Tf, the muon depolarisation adopts a simple exponential form, becoming a stretched exponential with exponent β approaching 0.5 as T→Tf. On cooling further, β drops further to 1 3 , and the depolarisation adopts a dynamic Kubo–Toyabe form which may be decoupled by applied longitudinal fields of the order of 5 kG. We estimate the upper limit of the static component of the moment to be 3.4 μB per iron ion, compared with a value of ≅5.92 μB expected for high-spin Fe3+. |
| Databáze: | OpenAIRE |
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