Heat transport in SrCu_2(BO_3)_2 and CuGeO_3
M. Hofmann, T. Lorenz, A. Freimuth, G.S. Uhrig, H. Kageyama, Y. Ueda, G. Dhalenne, A. Revcolevschi
Abstract
In the low dimensional spin systems SrCu_2(BO_3)_2 and CuGeO_3 the thermal conductivities along different crystal directions show pronounced double-peak structures and strongly depend on magnetic fields. For SrCu_2(BO_3)_2 the experimental data can be described by a purely phononic heat current and resonant scattering of phonons by magnetic excitations. A similar effect seems to be important in CuGeO_3, too but, in addition, a magnetic contribution to the heat transport may be present.