glide constant is extracted directly from the experimental data and is found to be moderately faster than single particle diffusion. We are also able to determine the parameters of the Peierls potential induced by the underlying crystalline lattice.There is considerable need for the rational design of new functional materials. One promising strategy is to build such materials from the bottom up by assembling mesoscale units which can then be linked into larger structures. The characteristics of such materials on the fundamental scale of the building blocks must be understood before they can be intelligently assembled into novel materials. In many cases the units in question possess surfaces with ordered arrays of particles; liposomes, colloidosomes, fullerenes and nanotubes provide prominent examples of such materials [1][2][3] . As in traditional 3D materials, the static structure and dynamic behaviour of defects, such as dislocations, is crucial in determining the response to mechanical, electrical and thermal stimuli 4 . In the ground state of planar 2D systems (flat space) all such defects are tightly bound. The role of thermally excited or mechanically induced defects has been thoroughly studied from both the theoretical and experimental side 5,6 .
We present an experimental system suitable for producing spherical crystals and for observing the distribution of lattice defects (disclinations and dislocations) on a significant fraction (50%) of the sphere. The introduction of fluorescently labeled particles enables us to determine the location and orientation of grain boundary scars. We find that the total number of scars and the number of excess dislocations per scar agree with theoretical predictions and that the geometrical centers of the scars are roughly positioned at the vertices of an icosahedron.
The suitability of amino acids and dipeptides as structure-directing agents for the deposition of coatings from aqueous solutions of zinc salts is discussed. According to a bio-inspired approach, the influence of these biomolecules was investigated with respect to the evolution of architectures based on zinc oxide and basic zinc salts. The small molecules were able to trigger the morphology of these materials ranging from grainlike to two-dimensional up to three-dimensional features. Besides morphological aspects, the structural characterization of these solids by means of electron and atomic force microscopies, photoelectron and infrared spectroscopies, and X-ray diffraction are discussed in order to extract the function of the biomolecules with regard to the formation of the inorganic phases.
When soluble zinc salts are hydrolyzed in water, usually elongated micrometer‐sized zincite crystals are formed. In this study, polyvinylpyrrolidone (PVP) in a methanolic solution is used as an agent to control the morphology of the deposition product. It prevents crystal growth and yields zinc oxide nanocrystals. Thin films consisting of zinc oxide nanocrystals are formed on self‐assembled monolayers (SAMs) of sulfonate‐terminated alkylsiloxanes. Patterned films are deposited after local decomposition of the SAM by UV irradiation. The films fabricated from methanolic solutions containing PVP are particularly smooth, uniform and stable. Their thickness is determined by the deposition time and the molar ratio [PVP]:[Zn2+], so that films of arbitrary thickness and nearly constant roughness can be obtained. The crystal grains are oriented preferentially with 〈001〉 direction perpendicular to the substrate surface. The films show ultraviolet, orange‐red and green‐yellow photoluminescence; the latter is quenched by heat treatment. Based on the obtained experimental results, a deposition mechanism is suggested.
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