Simplified Procedure for Estimating Epitaxy of ${\rm La}_{2}{\rm Zr}_{2}{\rm O}_{7}$ -Buffered NiW RABITS Using XRD

A procedure is developed for assessing the epitaxy of La_2- xZr₂₊ xO₇ (LZO) layers on NiW RABITS. Comparing XRD patterns ( thetas -2thetas scans and 2D rocking curves) of LZO films of known thickness (ellipsometry or reflectometry measurements) with those of standard samples (100% epitaxial LZO film and an isotropic LZO pellet of known density), we estimate the epitaxial (EF), and polycrystalline (PF) fractions of LZO within the layer. The procedure was tested using MOD-LZO(100 nm)/NiW tape samples with EF varied from 3 to 90% (reproducibly prepared by varying the humidity of Ar - 5%H₂ gas during heat treatment). A qualitative agreement with RHEED and quantitative (within plusmn 10%) agreement with the EBSD results was shown. Correlation between EF and J _c in 600 nm thick YBCO layer deposited on MOD-LZO/NiW using thermal coevaporation enables us to impose the EF = 80% margin on the quality of LZO layer for the particular conductor architecture.