Single-Crystal Growth and Thermal Conductivity of the Four-Leg Spin–Ladder System La₂Cu₂O₅

Abstract

We have succeeded in growing large-size single-crystals of the four-leg spin–ladder system La₂Cu₂O₅ by the traveling-solvent floating-zone method, and also investigated the thermal conductivity. The thermal conductivity along the leg of the ladder, κ_b, has been found to be much larger than that perpendicular to the ladder plane, κ_a. The temperature dependence of κ_b exhibits a peak at 22 K and a shoulder at 12 K. The peak is a little enhanced by the application of a magnetic field of 14 T. The large value of κ_b is explained as being due to the large contribution of magnons to the thermal conductivity.