Deposition and reduction of Nd1.85Ce0.15CuO4−<i>y</i> superconducting thin films

Abstract

Superconducting thin films of Nd1.85Ce0.15CuO4−y (NCCO) were grown at 720–820 °C by pulsed laser deposition in N2O atmosphere. The reduction subsequent to the deposition was found to be critical, and was studied systematically for various temperature, atmosphere, and duration. An ac susceptibility technique was used to stringently characterize the film quality. Very high quality films were made with optimized reduction conditions which showed a Tc(R=0) of 22.4 K, with a transition width of 0.2 K and a Jc (4.2 K) of 8×105/cm2 at zero field. Microwave surface resistance Rs was measured at 9.6 GHz and a value of ∼3 mΩ was obtained at 4.2 K in a 5000 Å thick NCCO film.