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CeO2 layers epitaxially grown on (100) silicon substrates by electron-beam evaporation were investigated and proved to have (110) orientation. X-ray diffraction measurements showed the CeO2 layers consist of more than 98% volume fraction of the (110) component. Cross-sectional high-resolution transmission electron microscopy and selected-area electron diffraction clearly verified the above configuration of crystallographic orientations and that the 〈100〉 direction in the CeO2(110) plane is parallel with the 〈110〉 direction in the Si(100) plane. The cross-sectional lattice image clarified the existence of a ∼60-Å-thick intermediate amorphous layer between the CeO2 layer and the silicon substrate. Moreover, the high density of defects such as dislocations and low-angle boundaries that exist in the vicinity of the interface agree well with Rutherford backscattering and channeling measurements.

Orientation selection in platinum films of ∼20 nm thickness deposited onto (001) MgO substrates by e-beam evaporation was investigated through ion beam channeling and x-ray diffraction. A mixture of crystallites having (111) and (001) orientation was observed in Pt films deposited over a range of substrate temperatures from 25 to 700 °C, with the (111) orientation dominant at low temperatures. The (111) orientation was present in these evaporated films at significantly higher substrate temperatures than reported for Pt films deposited by sputtering or pulsed laser deposition. Both orientations had strongly preferred in-plane orientations: [110] Pt//[110] MgO for the (001)-oriented crystallites and [110]Pt//[110] MgO for the (111). The orientation selection process was rationalized based on the expected relative interfacial energies for these two orientations.

We have grown a-axis oriented YBa2Cu3O7−x (YBCO) thin films on Si(100) substrates with (110) oriented insulating buffer layers of cerium dioxide (CeO2) using the pulsed laser deposition technique. The films are highly oriented and textured as determined by θ–2θ x-ray diffraction, x-ray pole-figure scan, scanning electron microscopy, Rutherford backscattering spectroscopy, and ion channeling. No diffusion at the interface has been found at growth temperatures up to 760 °C, indicating the CeO2 is a chemically stable and structurally compatible intermediate material for the growth of YBCO on Si. A zero resistance superconducting transition temperature of 87 K and a critical-current density (Jc) of 1.5×105 A/cm2 at 75 K have been measured; Jc obtained represents the highest value for the a-axis oriented YBCO films.

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