In-plane thermal conductivity of Nd2-xCexCuO4-y

We present measurements of ab-plane thermal conductivity (κ) for a series of Nd2-xCexCuO4-y single crystals (x=0.025, 0.15, 0.22) at T≤300 K. For all specimens κ increases with decreasing temperature, rises sharply for T<100 K, and reaches a maximum at T=20-30 K. Near room temperature κa12 W/mK for the insulator (x=0.025) and κa14-16 W/mK in superconducting (x=0.15) and metallic (x=0.22) specimens. These differences are attributed to differing electronic contributions to heat conduction. No anomaly in κ(T) was observed at the superconducting transition of the x=0.15 sample. For T<Tc, κ is suppressed slightly by the application of a strong magnetic field, consistent with an increase in phonon-electron scattering. The κ data are compared to previous results for the other cuprates.