Rapid Growth of Nd_2−xCe_xCuO₄ Thick Films as a Buffer for the Growth of Rare-earth Barium Cuprate–coated Conductors

Nd_2−xCe_xCuO₄ (x = 0 to 0.15) thick films were grown directly on LaAlO₃ substrates and surface-oxidized Ni tapes by fast liquid-phase processing methods. The films had a smooth surface and a very good biaxial texture, with the full width at halfmaximum equal to 0.8° and 5° on LaAlO₃ substrates and surface-oxidized Ni tapes, respectively. Films of thickness of 5–15 μmm were grown at rates in excess of 2 μm/min. Nd_2−xCe_xCuO₄ has a good lattice and thermal-expansion match to rare-earth Ba₂Cu₃O_7−δ (REBCO), minimum reaction with the high-temperature CuO:BaO solutions, and is nonpoisoning to superconductivity. It is an ideal buffer for liquidphase expitaxy processing of REBCO thick films.