Spin Order by Frustration in Triangular Lattice NaCrO$_2$ : A Neutron Scattering Study

ORAL

Abstract

We report high resolution neutron scattering measurements on the triangular lattice antiferromagnet NaCrO$_2$. In contrast to the host compound of the 2D cobaltate superconductor Na$_x$CoO$_2$, no magnetic long-range order is observed down to 1.5K. For $T >$ 40K purely 2D quasi-static 120$^{\circ}$ spin correlations extend to a maximum of 20 lattice constants. For $T <$ 30K, a small in-plane incommensuration develops together with short-range $c$-axis correlations. Our observation of strong spin fluctuations over an extended temperature range and a long wave-length incommensurate modulation strongly suggest an out-of-plane frustration as the mechanism for stabilizing this rare 2D correlated phase in NaCrO$_2$.

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Authors

  • D. Hsieh

    • Department of Physics, Princeton University

  • Dong Qian

    • Department of Physics, Princeton University
    • Princeton University

  • R.F. Berger

    • Department of Chemistry, Princeton University

  • B. Ueland

    • Department of Physics, Pennsylvania State University

  • P. Schiffer

    • Department of Physics, Pennsylvania State University

  • R.J. Cava

    • Princeton University
    • Princeton Univ.
    • Department of Chemistry, Princeton University
    • Department of Chemistry, Princeton University, Princeton, NJ 08540, USA
    • Department of Chemistry, Princeton University, Princeton NJ 08544, USA

  • J.W. Lynn

    • NIST Center for Neutron Research

  • Q. Huang

    • NIST Center for Neutron Research
    • NIST Center for Neutron Research, Gaithersburg, Maryland 20899

  • M.Z. Hasan

    • Department of Physics, Princeton University
    • Princeton University