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2D Kagome Ordering in the 3D Frustrated Spinel Li2Mn2O4

C. R. Wiebe·P. L. Russo·A. T. Savici·Y. J. Uemura·G. J. MacDougall·G. M. Luke·S. Kuchta·J. E. Greedan
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Abstract

muSR experiments on the geometrically frustrated spinel oxide, Li2Mn2O4, show the development of spin correlations over a range of length scales with decreasing temperature. Increased relaxation below 150 K is consistent with the onset of spin correlations. Below 50 K, spin order on a length scale, which is long range for the muSR probe, appears abruptly in temperature, consistent with prior neutron diffraction results. The oscillations in the zero field asymmetry are analyzed using a three frequency model. By locating the muon site this is shown to be consistent with the unexpected 2D q = root 3 x root 3 structure on the Kagome planes proposed originally from neutron data. Longitudinal field data demonstrate that some spin dynamics persist even at 2 K. Thus, a very complex magnetic ground state, featuring the co-existence of long length scale 2D ordering and significant spin dynamics, is proposed. This is unusual considering the 3D topology of the Mn3+ spins in this material.

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C. R. Wiebe, P. L. Russo, A. T. Savici, Y. J. Uemura, G. J. MacDougall, G. M. Luke, S. Kuchta, J. E. Greedan. 2005-07-15. 2D Kagome Ordering in the 3D Frustrated Spinel Li2Mn2O4. https://doi.org/10.1088/0953-8984%2F17%2F41%2F017

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