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YBa2Cu3O7−x (YBCO) films deposited by pulsed laser ablation on unbuffered and CeO2‐buffered yttria‐stabilized zirconia (YSZ) substrates were studied by x‐ray diffraction and transmission electron microscopy to investigate film orientation. From φ scans it was determined that the unbuffered films possess two major in‐plane orientation relationships with the substrate. Both have (001)YBCO∥(001)YSZ, with either [100]YBCO∥[100]YSZ or [110]YBCO∥[100]YSZ, a 0° or 45° orientation, respectively. As deposition temperature increases, satellite peaks that straddle the 0° or 45° orientations develop. The Σ boundary and near coincident site lattice descriptions are applied to the discussion of these misorientations. In general the CeO2‐buffered YBCO films align with to the 45° orientation to the CeO2 buffer layer. Out‐of‐plane film orientation was investigated for both unbuffered and CeO2‐buffered YBCO films and expressed as a ratio of the amount of c⊥ material to a⊥ material. Buffered films exhibited c⊥ material to a...

Thick film (1.2 μm) YBCO superconductors grown by pulsed laser deposition on unbuffered and CeO2-buffered single crystal (001)-oriented yttria-stabilized zirconia (YSZ) substrates have been investigated. YBCO and YSZ react to form BaZrO3 (BZO), whereas YBCO and CeO2 react to form BaCeO3. Reaction phases were examined by θ-2θ and four-circle x-ray diffraction and high resolution electron microscopy. Three orientation relationships identified for the unbuffered films were (i) (001)YBCO ‖ (011)BZO ‖ (001)YSZ with [110]YBCO ‖ [100]BZO ‖ [100]YSZ, (ii) (001)YBCO ‖ (001)BZO ‖ (001)YSZ with [110]YBCO ‖ [100]BZO ‖ [100]YSZ, and (iii) (001)YBCO ‖ (001)BZO ‖ (001)YSZ with [100]YBCO ‖ [100]BZO ‖ [100]YSZ. The results suggest that for films grown at typical deposition temperatures, YBCO epitaxy is established before the interfacial reaction occurs. The presence of BaCeO3 in buffered films grown at high temperatures (790 °C) was confirmed by θ-2θ scans and selected area diffraction patterns.

Surface and grain topography of YBa 2 Cu 3 O 7− x epitaxial thin films grown on (100) NdGaO 3 using pulsed laser deposition has been studied using atomic force and scanning tunneling microscopy under ambient conditions. X-ray diffraction and transmission electron microscopy results support the force microscopy findings. Parametric studies of the effect of substrate temperature, annealing time and deposition rate were performed on 33 nm thick films. The observed island re-orientation as a function of time-at-temperature suggest that under our epitaxial growth conditions, the nuclei ripening time can be on the order of seconds. Implications for the observed island structure on transport and microwave surface resistance properties are briefly discussed.