We present the results of measurements of the thermal conductivity κ of the spin S=1 chain compound AgVP_2S_6 in the temperature range between 2 and 300 K and with the heat flow directed either along or perpendicular to the chain direction. The analysis of the anisotropy of the heat transport allowed for the identification of a small but non-negligible magnon contribution κm along the chains, superimposed on the dominant phonon contribution κph. At temperatures above about 100 K the energy diffusion constant D_E(T), calculated from the κm(T) data, exhibits similar features as the spin diffusion constant D_S(T), previously measured by NMR. In this regime, the behaviour of both transport parameters is consistent with a diffusion process that is caused by interactions inherent to one-dimensional S=1 spin systems.
@article{arxiv.cond-mat/0307383,
title = {Diffusive energy transport in the S=1 Haldane chain compound AgVP2S6},
author = {A. V. Sologubenko and S. M. Kazakov and H. R. Ott and T. Asano and Y. Ajiro},
journal= {arXiv preprint arXiv:cond-mat/0307383},
year = {2009}
}