Thermal conductivity of single crystal lanthanum cuprates at very low temperature

We have undertaken a study of the thermal conductivity of single crystals of pure and strontium doped lanthanum copper oxide in the temperature range 0.1–6 K. For in plane conduction, all samples show approximately a T 2.7 dependence, whereas for conduction across the planes for x = 0 we observe κ ∼ T 2. This suggests that dimensionality may play an important role in the lattice heat conduction properties of these materials at very low temperature.