Transmission electron microscopy analysis of a coated conductor produced by chemical deposition methods

A water-based precursor solution was used to deposit a thin La2Zr2O7La2Zr2O7 layer (70 nm) on a NiW substrate. The characterization of the La2Zr2O7La2Zr2O7 (LZO) consisted of X-ray diffraction, pole figures, reflection high-energy electron diffraction, scanning electron microscopy, atomic force microscopy and transmission electron microscopy (TEM) of the cross-section. The results reveal that high-quality LZO layers can be produced using completely water-based solutions, rendering a high degree of texture (full width at half maximum = 6.5°). In order to test the quality of this coating as a buffer layer, a 350 nm thick layer of YBCO was deposited by metal organic chemical vapor deposition. The superconducting properties were measured inductively (Cryoscan, THEVA). A thorough TEM study of all the interfaces present was carried out. Several secondary phases were found at these interfaces. Since the buffer layer was thin, oxidation of the substrate could not be prevented.