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

The anisotropic conductivity of thin Nd1.85Ce0.15CuO4-delta films was measu red in the frequency range 8<nu <40 cm(-1) and for temperatures 4<T<300 It. A tilted sample geometry made it possible to extract both in-plane and c-a xis properties. The in-plane quasiparticle scattering rate remains unchange d 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 beha vior within the plane.