The room-temperature epitaxial growth of ZnO thin films on NiO buffered sapphire (0001) substrate was achieved by using the laser molecular-beam-epitaxy method. The obtained ZnO films had the ultrasmooth surface reflecting the nanostepped structure of the sapphire substrate. The crystal structure at the surface was investigated in situ by means of coaxial impact-collision ion scattering spectroscopy. It was proved that the buffer-enhanced epitaxial ZnO thin films grown at room temperature had +c polarity, while the polarity of high-temperature grown ZnO thin films on the sapphire was −c. Photoluminescence spectra at room temperature were measured for the epitaxial ZnO films, showing only the strong ultraviolet emission near 380nm.

We investigated atomic-scale surface modifications of silicate glass by nanoimprint using an atomically stepped sapphire (α-Al2O3 single crystal) plate as nanopattern mold. The sapphire mold had regularly arranged straight atomic steps, with uniform height and terrace width of about 0.2 and 80 nm, respectively. During pressing, vertical positions of the sapphire mold and glass plate significantly affected the morphology of the imprinted glass surface. The nanopattern was transferred to the glass surface when the mold was set on the glass plate, while the nanowave pattern was formed on the glass surface when the glass plate was set on the mold.

Thin-film epitaxy is critical for investigating the original properties of materials. To obtain epitaxial films, careful consideration of the external conditions, i.e. single-crystal substrate, temperature, deposition pressure and fabrication method, is significantly important. In particular, selection of the single-crystal substrate is the first step towards fabrication of a high-quality film. Sapphire (single-crystalline α-Al2O3) is commonly used in industry as a thin-film crystal-growth substrate, and functional thin-film materials deposited on sapphire substrates have found industrial applications. However, while sapphire is a single crystal, two types of atomic planes exist in accordance with step height. Here we discuss the need to consider the lattice mismatch for each of the sapphire atomic layers. Furthermore, through cross-sectional transmission electron microscopy analysis, we demonstrate the uniepitaxial growth of cubic crystalline thin films on bistepped sapphire (0001) substrates.

We performed atomic-scale surface patterning with a vertical resolution of approximately 0.3 nm on a poly(methyl methacrylate) (PMMA) polymer sheet (10 ' 10 mm 2 ) by thermal nanoimprinting using an atomically stepped sapphire template (α-Al 2 O 3 single crystal). The sapphire mold with (10 12) r-plane exhibited regularly arranged straight steps with a uniform height of approximately 0.31 nm. The template nanopattern could be transferred onto the surface of the PMMA sheet under the imprinting conditions of 0.2 MPa load for 300 s at 140°C. Atomic stairs with approximately 0.26-nm-high straight steps and approximately 600-nm-wide terraces were formed on the PMMA surface.

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