Low-temperature heat transport of Nd_2CuO_4: Roles of Nd magnons and   spin-structure transitions
  We report the magnetic-field dependence of thermal conductivity (\kappa) of an insulating cuprate Nd_2CuO_4 at very low temperatures down to 0.3 K. It is found that apart from the paramagnetic moments scattering on phonons, the Nd^{3+} magnons can act as either heat carriers or phonon scatterers, which strongly depends on the long-range antiferromagnetic transition and the field-induced transitions of spin structure. In particular, the Nd^{3+} magnons can effectively transport heat in the spin-flopped state of the Nd^{3+} sublattice. However, both the magnon transport and the magnetic scattering are quenched at very high fields. The spin re-orientations under the in-plane field can be conjectured from the detailed field dependence of \kappa. 
Z. Y. Zhao, X. M. Wang, B. Ni, Q. J. Li, C. Fan, W. P. Ke, W. Tao, L.   M. Chen, X. Zhao, X. F. Sun (USTC)
cond-mat.str-el