a1 Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831
Polychromatic synchrotron x-ray microdiffraction is used to determine the epitaxy of YBa2Cu3Ox (YBCO) films grown on polycrystalline Y.15Zr.85O1.925/CeO2/Y2O3/Ni95W5(Ni) rolling-assisted, biaxially textured substrates (RABiTS). A novel analysis technique is introduced in which the orientation of mosaic films is measured by using a Hough transform to recognize arcs in Laue microdiffraction patterns that correspond to low-index zone axes. While the overall epitaxy is cube-on-cube, grain-by-grain analysis reveals a systematic misorientation of YBCO with respect to Ni: the YBCO  rotates toward the direction of the surface normal. The crystal mosaic (for rotation about the rolling direction) measured by a single diffraction pattern sampling a 0.5-μm2 surface area is 0.7° full width at half-maximum for YBCO grown on Ni grains with a low tilt; for more highly tilted grains, the YBCO patterns can no longer be measured, presumably due to the large mosaic. The YBCO mosaic over the entire area of a Ni grain is ∼2.5° and varies with grain size; the mosaic is smaller for larger grains.
(Received August 07 2006)
(Accepted November 01 2006)
p1 Present address: Argonne National Laboratory, Argonne, Illinois 60439.
b) This author was an editor of this journal during the review and decision stage. For the JMR policy on review and publication of manuscripts authored by editors, please refer to http://www.mrs.org/jmr_policy.