Transport properties of rare earth doped La2−xSrxCuO4

We present measurements of the resistivity, the thermopower, and the thermal conductivity of rare earth (RE) doped La_2–xSr_xCuO₄. Pronounced anomalies occur at the low temperature structural phase transition showing that the electronic properties as well as the lattice dynamics depend strongly on small structural changes. Our results indicate that a suppressed phonon heat transport is a characteristic feature of La₂CuO₄ based superconductors. A possible relationship to the presence of stripe correlations of holes and spins in doped La₂CuO₄ is discussed.This work was supported by the DFG through SFB 341. We thank W. Brenig and A.P. Kampf for many stimulating discussions.