Thermal Conductivity of the S = 1/2 Quasi-One-Dimensional Ferromagnetic Spin System CsCuCl3

We have measured the thermal conductivity along the c-axis, κ||c, parallel to ferromagnetic spin-chains of single crystals of the S = 1/2 quasi-one-dimensional spin system CsCuCl3 in magnetic fields up to 14 T, in order to investigate the thermal conductivity due to spins, κspin, and the change of thermal conductivity corresponding to the change of the spin state. In the temperature dependence of κ||c, no contribution of κspin has been observed, while a dip has been observed at the antiferromagnetic phase transition temperature, TN. Furthermore, it has been found that κ||c at a low temperature of 5.1 K below TN changes with increasing field perpendicular to the c-axis in good correspondence to the field-induced change of the spin state.