Anisotropic conductivity of Nd1.85Ce0.15CuO4-δ a films at submillimeter wavelengths

The anisotropic conductivity of thin Nd1.85Ce0.15CuO4-delta films was measured in the frequency range 8<40 cm(-1) and for temperatures 4<300 It. A tilted sample geometry made it possible to extract both in-plane and c-axis properties. The in-plane quasiparticle scattering rate remains unchanged as the sample becomes superconducting. The temperature dependence of the in-plane conductivity is reasonably well described using the Born limit for a ri-wave superconductor. Below Tc, the c-axis dielectric constant epsilon(1c), changes sign at the screened c-axis plasma frequency. The temperature dependence of the c-axis conductivity closely follows the linear in T behavior within the plane.