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We investigated the structure and alignment of epitaxial Y2O3 and Gd2O3 films on cube textured Ni(0 0 1) substrates and used the findings to develop a general interpretation of the morphology of RE2O3 films (RE=Y or a rare earth element) on cube textured nickel and nickel-based alloys. The [1 0 0] axis of RE2O3 oxides mostly prefers aligning to the Ni[1 1 0] axis, while the [0 0 1] axis is aligned with the Ni[0 0 1] axis. This (2 2 ×2 2 )R45° extended domain matching (EDM) seems to be favored by a high coincidence site density (CSD) with the Ni(0 0 1) surface atoms, in spite of the existence of large lattice mismatches to Ni(0 0 1). Meanwhile a 3×3 EDM is not favored on Ni(0 0 1), in spite of the relatively small lattice mismatch to Ni(0 0 1), because of the existence of a low CSD. The broad mosaic distributions of RE2O3(0 0 l) grains (6–9° full-width at half-maximum) indicate that RE2O3 layers prefer growing along the Ni(0 0 1) planes rather than along the Ni surface, a condition presumably induced by the favorable energetics for EDM.

We studied the microstructure of a Pd overlayer deposited on a cube textured Ni(0 0 1) substrate using synchrotron X-ray scattering. We find the existence of an epitaxial Pd–Ni interlayer between the epitaxial Pd layer and the Ni substrate. The Pd–Ni interlayer, which is compressively strained in a manner similar to the Pd overlayer, seemingly acts to relieve the strain at the Pd/Ni interface caused by the Pd–Ni lattice mismatch. The Ni mosaic distribution of our samples is multiply spiked with a rocking angle spread of ∼16°, which reconciles the previously reported observation of saw tooth peaks on top of a Gaussian distribution for a similarly prepared Pd on Ni specimen. The observed sharpening of the mosaic distributions for the Pd(0 0 2) grains (full-width at half-maximum (FWHM)=1.95°) and for the (0 0 2) grains of Pd–Ni interlayer (FWHM=3.0°) indicates that the Pd and Pd–Ni(0 0 2) layers conform to the surface morphology instead of to the (0 0 1) crystallographic planes of Ni-substrate grains.