Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition

Leopoldo Molina-Luna, Ricardo Egoavil, Stuart Turner, Thomas Thersleff, Jo Verbeeck, Bernhard Holzapfel, Oliver Eibl, Gustaaf Van Tendeloo
2013 Superconductors Science and Technology  
The functionality of YBa 2 Cu 3 O 7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)-metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on
more » ... O 2 /La 2 Zr 2 O 7 and grown on a flexible Ni5 at.%W substrate with a {100} 001 biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a j c of 1.02 MA cm −2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO 2 /La 2 Zr 2 O 7 region (10 nm interlayer) and (ii) the La 2 Zr 2 O 7 /Ni-5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition.
doi:10.1088/0953-2048/26/7/075016 fatcat:c74ahglxfrdofn5hbu6dirgvmi