[en] Ba₆Mg₁₁F₃₄, a new compound of the pseudobinary BaF₂-MgF₂ system, has been synthesized by solid state techniques from stoichiometric amounts of BaF₂ and MgF₂ and its crystal structure determined by single crystal X-ray diffraction (space group P1-bar, a=7.5084(6), b=9.9192(8), c=10.0354(8) A, α=81.563(2), β=72.402(2), γ=71.198(1) deg., 3899 structure factors, 233 parameters, R(F²>2σ(F²))=0.018, wR(F² all) = 0.046). It is isotypic with the copper(II) analogue, Ba₆Cu₁₁F₃₄. The main features of the structure are a network of [MgF₆] octahedra and three different [BaF_x] polyhedra with x=12, 11+1 and 13. Ba₆Mg_11-xFe_xF₃₄ and Ba₆Mg_11-xMn_xF₃₄ solid solutions were prepared and their composition determined by single crystal structure analyses. The luminescence properties of Ba₆Mg₁₁F₃₄ doped with Eu²⁺ were studied using fluorescence spectroscopy. The observed luminescence was pale blue with a maximum at 465 nm

[en] Ninety-eight patients with locally advanced breast cancer (Stage IIIA-IIIB) were entered into a pilot study combining intensive induction (neoadjuvant) chemotherapy (VTMFAP) with or without hormonochemotherapy, external and interstitial radiotherapy, and consolidation chemotherapy with or without hormonochemotherapy. Tumor regression over 50% was observed in 91% patients after chemotherapy, and complete clinical remission occurred in 100% patients after irradiation. The rate of local relapse is 13%. The 3-year disease-free survival is 62% and 3-year global survival is 77%. Initial chemotherapeutic tumor regression greater than 75% is the main predictive factor for disease-free survival

[en] We report on an experimental study of the morphological and chemical evolution of the (1 0 0) InAs surface under 50 keV focused Ga⁺ ion beam exposure using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Auger electron spectroscopy (AES). For ion fluences higher than 1.25 x 10¹⁶ ions/cm² the formation of crystallite like microprotrusions on a (1 0 0) InAs surface has been observed by scanning electron microscopy (SEM). The size of the microprotrusions increases with increasing ion fluence and achieves ranges from 30 nm to 1.5 μm while the surface density decreases. Combining XRD and AES results proved that focused ion beam (FIB) bombardment of the InAs surface leads to the formation of nearly pure indium crystallites obviously due to a preferential loss of arsenic atoms during FIB sputtering

[en] The development of new technologies is often connected with the use of non-renewable resources. In recent years a qualitative shift in the demand of bulk metals (e.g. Fe, Al, Cu) to more scarce metals (e.g. Te, Ga, Re) is recognizable. Novel technologies and products rely more and more on very specific metals which are indispensable for their function. Although such metals are generally used in low concentrations in products, the demand has raised significantly due to mass production. Some of them are of high importance due to their strategic relevance to emerging innovative technologies. Lithium so far has gained relatively little attention, although it fulfills the main criteria of a strategically relevant metal. In recent years, however, recognition of lithium increased as a result of the growing market for lithium-based chargeable batteries in mobile information/communication consumer products and in electric vehicles. Both areas of demand led to a skyrocketed use of lithium in recent years. Other technologies in the future like fusion power generation will raise lithium consumption at an accelerated rate. It is therefore necessary to determine the availability of lithium in the medium and long term in order to prevent technology failures and to ensure a more sustainable development. The authors will provide a well founded knowledge base, outline the availability of worldwide reserves and resources, and describe the structure of present and future demands for lithium. (authors)

No abstract available

[en] New materials on nano scale have the potential to overcome existing technical barriers and are one of the most promising key technologies to enable the decoupling of economic growth and resource consumption. Developing these innovative materials for industrial applications means facing a complex quality profile, which includes among others technical, economic, and ecological aspects. So far the two latter aspects are not sufficiently included in technology development, especially from a life cycle point of view. Supercapacitors are considered a promising option for electric energy storage in hybrid and full electric cars. In comparison with presently used lithium based electro chemical storage systems supercapacitors possess a high specific power, but a relatively low specific energy. Therefore, the goal of ongoing research is to develop a new generation of supercapacitors with high specific power and high specific energy. To reach this goal particularly nano materials are developed and tested on cell level. In the presented study the ecological implications (regarding known environmental effects) of carbon based nano materials are analysed using Life Cycle Assessment (LCA). Major attention is paid to efficiency gains of nano particle production due to scaling up of such processes from laboratory to industrial production scales. Furthermore, a developed approach will be displayed, how to assess the environmental impact of nano materials on an automotive system level over the whole life cycle.

[en] We have studied the evolution of the GaAs, InAs and GaSb surfaces due to FIB exposure. In contrast to conventional bottom up or top down processes the observed nanopattern formation is discussed, based on a subtractive self-organization process relying on material decomposition induced by FIB exposure

[en] In this work, we present an experimental study of the morphological and chemical evolution of the (1 0 0) GaSb surface after 50 keV focused Ga⁺ ion beam exposure using scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy and room temperature raman measurements. A honeycomb-like structure consisting of many cells evolved under the GaSb surface implanted with 50 keV Ga⁺ ions for ion fluences of 2.5 x 10¹⁵ ions/cm². The cell diameter and the thickness of the walls partitioning the cells were about 60 and 20 nm respectively. During further FIB implantation the subsurface cavities expanded in the surface direction and form a microtexture of filaments about 25 nm in diameter. Above a Ga fluence of 6.25 x 10¹⁶ ions/cm² the onset of nanofibers growth was observed taking place in close proximity to the FIB modified surface. The nanofibers are amorphous with remarkably uniform diameters in the range of about 25 nm incorporating GaSb nanocrystallites with cubic zinc blende structure. A growth model is proposed based on the idea of a catalytic vapour liquid solid nanowire growth mechanism

[en] Mn₃TeO₆ has a trigonal corundum related structure (space group $R\stackrel{¯<!--\; ??\; -->}{3}$), and orders in an incommensurate antiferromagnetic (AFM) structure at T _N $\approx <!--\; ???\; -->$ 24 K. A weak ferroelectric order below T  ^* ∼ 21 K has recently been reported. In order to investigate possible structural changes below T _N leading to the observed dipole order, we have performed a detailed study of the crystal and magnetic structures of Mn₃TeO₆ using neutron powder diffraction (NPD) in the temperature range of 5–40 K. Complementary low-temperature second harmonic generation (SHG) measurements were performed in order to confirm the reported dipole order at T  ^*. No change in the rhombohedral symmetry associated with a possible displacive phase transition at T  ^* was observed in the long-range structural correlations, and it appears that Mn₃TeO₆ keeps the same incommensurately modulated magnetic spin structure with the propagation vector k  =  (0; 0; 0.43) in the whole temperature range from 5 to 24 K. (paper)

[en] Highlights: • Magnetic study of single-crystalline Co_3−xZn_xTeO₆, complemented by NPD on powder samples • Change in the magnetic structure and range of the magnetic interaction for Zn> 10% • Phase diagram showing evolution of magnetic interaction strength with increasing Zn • Clear correlation of the magnetic properties with the average Co2/Zn2-O bond length -- Abstract: The magnetic properties of phase-pure solid solutions of Co_3−xZn_xTeO₆ are investigated using magnetometry (single crystals) and neutron diffraction (polycrystalline powders), and compared to results of detailed crystallographic studies. There are five unique Co sites in Co₃TeO₆, including a tetrahedrally coordinated Co2 site which Zn preferentially occupies. The magnetic interaction is found to monotonically decrease as the Co2-O bond length decreases with increasing Zn content. The results suggest a modification of the magnetic structure in the samples containing Zn.