Preparation of Double Perovskite Ca2NiWO6 as a Buffer Layer for YBa2Cu3O7−δ Coated Conductors

Ca2NiWO6 films were deposited on the Y-stabilized ZrO2 (100) (YSZ) single crystalline substrates by pulsed laser deposition process. X-ray diffraction reveals that the Ca2NiWO6 film is coherently strained due to the small lattice mismatch between Ca2NiWO6 and YSZ substrate. With this c-axis orientated Ca2NiWO6 film as buffer layer, YBa2Cu3O7−δ film has been successfully prepared by pulsed laser deposition. The subsequently deposited YBa2Cu3O7−δ film has a preferred c-axis orientation and a smooth surface. The temperature dependence of resistance indicates a superconducting critical temperature higher than 82 K. Our results demonstrate that the double perovskite Ca2NiWO6 is a promising buffer layer candidate for coated conductors.