Transport and structural characterization of epitaxial Nd_1+xBa_2-xCu₃O_y thin films grown on LaAlO₃ and Ni metal substrates by pulsed-laser deposition

The epitaxial growth and properties of Nd_1+xBa_2-xCu₃O_y (NdBCO) thin films using pulsed-laser deposition are reported. Thin films on single crystal LaAlO₃ having T_c0 = 93 K and J_c(H = 0, T = 77 K) = 3 MA/cm² were reproducibly fabricated. NdBCO films were subsequently grown on textured Ni substrates on which a YSZ/CeO₂ buffer-layer architecture was previously deposited by the same PLD technique. X-ray diffraction data showed a high degree of in-plane and out-of-plane alignment for the different layers of these coated conductors. Electron diffraction analysis of the NdBCO film revealed dense morphology and low-angle grain boundaries (≤3°). Direct current transport measurements yielded a J_c of about 300 kA/cm² at zero field and 77 K. J_c dependence on the field intensity and orientation revealed enhanced pinning at high fields with respect to YBCO and NdBCO films on LaAlO₃.