Influence of magnetic field on thermal conductivity of La2- xSrxCuO4 single crystals
磁场对La2－xSrxCuO4单晶热导的影响研究

We have measured the temperature dependence of thermal conductivity in the ab-plane as well as c-axis of a series of underdoped La_ 2-xSr_xCuO_4 (x=0.063, 0.070, 0.090, 0.110, 0.125) single crystals under zero and 14 T magnetic field. It is found that the thermal conductivity in both ab plane and c-axis are suppressed by the application of the magnetic field parallel to the c-axis. The temperature dependence of the thermal conductivity suppression is quite similar to the previously reported behavior of the antiferromagnetic order induced by an applied magnetic field. We think that the field-induced thermal conductivity suppression in ab plane is due to the electronic contribution, while along c-axis it is due to the phonon contribution. Both the suppressions of the thermal conductivity in ab plane and along c-axis probably originate from the field-enhanced charge and spin ordering.