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arXiv · 1405.6184

Spin Order by Quantum Frustration in Triangular Lattice Mott Insulator NaCrO2 : A Neutron Scattering Study

D. Hsieh·D. Qian·R. F. Berger·C. Liu·B. Ueland·P. Schiffer·Q. Huang·R. J. Cava·J. W. Lynn·M. Z. Hasan
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Abstract

We report high resolution neutron scattering measurements on the triangular lattice Mott insulator Na$_x$CrO$_2$ ($x$=1) which has recently been shown to exhibit an unusually broad fluctuating crossover regime extending far below the onset of spin freezing ($T_c\sim$41K). Our results show that below some crossover temperature ($T\sim0.75T_c$) a small incommensuration develops which helps resolve the spin frustration and drives three-dimensional magnetic order supporting coherent spin wave modes. This incommensuration assisted dimensional crossover suggests that inter-layer frustration is responsible for stabilizing the rare 2D correlated phase above 0.75$T_c$. In contrast to the host compound of 2D cobaltate superconductor such as Na$_x$CoO$_2$ ($ξ_c>50$Å), no magnetic long-range order is observed down to 1.5K ($ξ_c<16$Å).

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D. Hsieh, D. Qian, R. F. Berger, C. Liu, B. Ueland, P. Schiffer, Q. Huang, R. J. Cava, J. W. Lynn, M. Z. Hasan. 2014-05-23. Spin Order by Quantum Frustration in Triangular Lattice Mott Insulator NaCrO2 : A Neutron Scattering Study. https://arxiv.org/abs/1405.6184

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