The planes occurring at convex corners during anisotropic etching of (100)-silicon in aqueousKOH were identified as {411}-planes, with the help of a specially developed measuring technique. The etching rate of these planes in relation to the rate of the {100}-planes declines with increasing potassium hydroxide concentration. In contrast, the temperature dependence of this etch rate ratio is negligible in the relevant range between 60~ and 100~ Based on these results, special structures suited for the compensation of the undercutting in the case of very narrow contours were developed. With the help of these structures it is feasible to realize, for instance, bent V-grooves or structures with a very low ratio between lateral expansion and etching depth, e.g., a discrete pyramid-trunk with minimum dimensions on the wafer surface. This offers access to completely new applications, among others spiral channels with double-sided anisotropic etching for micro-

Here we present a study of the electronic structure of epitaxial ferromagnetic Mn 5 Ge 3 (0001) films on Ge(111) by means of x-ray absorption spectroscopy, x-ray photoelectron spectroscopy, and spin-resolved photoelectron spectroscopy. Spin-polarization (P ) value of +(15 ± 5)% at the Fermi energy (E F ) is measured with a photon energy of hν = 21.2 eV. Our findings are in contrast to recent band structure calculations predicting P = −41% at E F for the ferromagnetic bulk Mn 5 Ge 3 .

Zinc oxide (ZnO) nanocrystals (NCs) with high crystalline quality were prepared via radio-frequency magnetron sputtering as a SiO 2 /ZnO/SiO 2 trilayer on Si(100) and Al 2 O 3 (0001) substrates with an intermediate in situ annealing step. Transmission electron microscopy reveals a uniform dispersion of ZnO NCs in the amorphous SiO 2 matrix with typical sizes up to 16 nm with a larger fraction of smaller crystals. The size distribution analysis yields a mean grain size of 5 nm for small particles. Individual ZnO NCs show a well-defined hexagonal close packed wurtzite structure and lattice parameters close to those of bulk ZnO, confirming their high crystalline quality. Mapping of the Zn distribution by means of energy-filtered transmission electron microscopy reveals a strongly non-uniform distribution of Zn within the SiO 2 matrix, corroborating the chemical separation of ZnO NCs from surrounding SiO 2 . Optical transmittance measurements confirm the findings of the electron microscopy analysis. The fabrication technique described opens up new possibilities in the preparation of ZnO NCs with high crystalline quality, including growth in monolithic optical cavities without intermediate ex situ fabrication steps.

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Metallic nanostructures play an important role in the vast field of modern nanophotonics, which ranges from the life sciences to biomedicine and beyond. Gold is a commonly-used and attractive material for plasmonics in the visible wavelength range, most importantly due to its chemical stability. In the present work, we focused on the different methods of plasmonic nanostructure fabrication that possess the greatest potential for cost-efficient fabrication. Initially, reusable (1 0 0) silicon templates were prepared. For this purpose, three different lithography methods (i.e. e-beam, optical, and nanoparticle lithography) were used that correspond to the desired structural scales. The application of a subsequent anisotropic crystal orientation-dependent wet etching process produced well-defined pyramidal structures in a wide variety of sizes, ranging from several microns to less than 100 nm. Finally, a 200 nm-thick gold layer was deposited by means of confocal sputtering on the silicon templates and stripped in order to obtain gold films that feature a surface replica of the initial template structure. The surface roughness that was achieved on the stripped films corresponds well with the roughness of the template used. This makes it possible to prepare cost-efficient high-quality structured films in large quantities with little effort. The gold films produced were thoroughly characterized, particularly with respect to their plasmonic response.