Fabrication and characterization of La2Zr2O7 films on different buffer architectures for YBa2Cu3O7−δ coated conductors by RF magnetron sputtering

Abstract

La 2 Zr 2 O 7 (LZO) films were grown on different buffer architectures by radio frequency magnetron sputtering for the large-scale application of YBa 2 Cu 3 O 7− x (YBCO)-coated conductors. The three different buffer architectures were cerium oxide (CeO 2 ), yttria-stabilized zirconia (YSZ)/CeO 2 , and CeO 2 /YSZ/CeO 2 . The microstructure and surface morphology of the LZO film were studied by X-ray diffraction, optical microscopy, field emission scanning electron microscopy, and atomic force microscopy. The LZO films prepared on the CeO 2 , YSZ/CeO 2 , and CeO 2 /YSZ/CeO 2 buffer architectures were preferentially c -axis-oriented and highly textured. The in-plane texture of LZO film on CeO 2 single-buffer architecture was ∆ φ = 5.5° and the out-of-plane texture was ∆ ω = 3.4°. All the LZO films had very smooth surfaces, but LZO films grown on YSZ/CeO 2 and CeO 2 /YSZ/CeO 2 buffer architectures had cracks. The highly textured LZO film grown on CeO 2 -seed buffered NiW tape was suitable for the epitaxial growth of YBCO film with high currents.