We report high resolution neutron scattering measurements on the triangular lattice Mott insulator NaxCrO2 (x=1) which has recently been shown to exhibit an unusually broad fluctuating crossover regime extending far below the onset of spin freezing (Tc∼41K). Our results show that below some crossover temperature (T∼0.75Tc) 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 0.75Tc. In contrast to the host compound of 2D cobaltate superconductor such as NaxCoO2 (ξc>50\AA), no magnetic long-range order is observed down to 1.5K (ξc<16\AA).
@article{arxiv.1405.6184,
title = {Spin Order by Quantum Frustration in Triangular Lattice Mott Insulator NaCrO2 : A Neutron Scattering Study},
author = {D. Hsieh and D. Qian and R. F. Berger and C. Liu and B. Ueland and P. Schiffer and Q. Huang and R. J. Cava and J. W. Lynn and M. Z. Hasan},
journal= {arXiv preprint arXiv:1405.6184},
year = {2014}
}