@misc{KrammLefevreBogdanoffetal., author = {Kramm, Ulrike Ingrid and Lef{\`e}vre, Michel and Bogdanoff, Peter and Schmeißer, Dieter and Dodelet, Jean-Pol}, title = {Analyzing Structural Changes of Fe-N-C Cathode Catalysts in PEM Fuel Cell by M{\"o}ßbauer Spectroscopy of Complete Membrane-Electrode-Assemblies}, series = {The Journal of Physical Chemistry Letters}, volume = {2014}, journal = {The Journal of Physical Chemistry Letters}, number = {5}, issn = {1948-7185}, doi = {10.1021/jz501955g}, pages = {3750 -- 3756}, abstract = {The applicability of analyzing by M{\"o}ßbauer spectroscopy the structural changes of Fe-N-C catalysts that have been tested at the cathode of membrane electrode assemblies in proton exchange membrane (PEM) fuel cells is demonstrated. The M{\"o}ßbauer characterization of powders of the same catalysts was recently described in our previous publication. A possible change of the iron species upon testing in fuel cell was investigated here by M{\"o}ßbauer spectroscopy, energy-dispersive X-ray cross-sectional imaging, and neutron activation analysis. Our results show that the absorption probability of γ rays by the iron nuclei in Fe-N-C is strongly affected by the presence of Nafion and water content. A detailed investigation of the effect of an oxidizing treatment (1.2 V) of the non-noble cathode in PEM fuel cell indicates that the observed activity decay is mainly attributable to carbon oxidation causing a leaching of active iron sites hosted in the carbon matrix.}, language = {en} } @misc{IndraMenezesSahraieetal., author = {Indra, Arindam and Menezes, Prashanth W. and Sahraie, Nastaran Ranjbar and Bergmann, Arno and Das, Chittaranjan and Tallarida, Massimo and Schmeißer, Dieter and Strasser, Peter and Driess, Matthias}, title = {Unification of Catalytic Water Oxidation and Oxygen Reduction Reactions: Amorphous Beat Crystalline Cobalt Iron Oxides}, series = {Journal of the American Chemical Society}, volume = {2014}, journal = {Journal of the American Chemical Society}, number = {136}, issn = {1520-5126}, doi = {10.1021/ja509348t}, pages = {17530 -- 17536}, abstract = {Catalytic water splitting to hydrogen and oxygen is considered as one of the convenient routes for the sustainable energy conversion. Bifunctional catalysts for the electrocatalytic oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are pivotal for the energy conversion and storage, and alternatively, the photochemical water oxidation in biomimetic fashion is also considered as the most useful way to convert solar energy into chemical energy. Here we present a facile solvothermal route to control the synthesis of amorphous and crystalline cobalt iron oxides by controlling the crystallinity of the materials with changing solvent and reaction time and further utilize these materials as multifunctional catalysts for the unification of photochemical and electrochemical water oxidation as well as for the oxygen reduction reaction. Notably, the amorphous cobalt iron oxide produces superior catalytic activity over the crystalline one under photochemical and electrochemical water oxidation and oxygen reduction conditions.}, language = {en} } @incollection{NarraLogschGlaseretal., author = {Narra, Satyanarayana and Logsch, Florian and Glaser, Claudia and Ay, Peter and D{\"o}hling, Frank and Leistner, Diana and Strube, Dieter}, title = {LignoBioFuel : Entwicklung eines Verfahrens zur Herstellung von stofflich und energetisch nutzbaren Bioagglomeraten auf der Basis von Lignin}, series = {Effizient, umweltvertr{\"a}glich, dezentral - neue Konzepte f{\"u}r die Nutzung von biogenen Festbrennstoffen, Bd. 2}, booktitle = {Effizient, umweltvertr{\"a}glich, dezentral - neue Konzepte f{\"u}r die Nutzung von biogenen Festbrennstoffen, Bd. 2}, editor = {Thr{\"a}n, Daniela and Pfeiffer, Diana}, publisher = {DBFZ, Dt. Biomasseforschungszentrum}, address = {Leipzig}, pages = {85 -- 99}, language = {de} } @inproceedings{SeifarthWalczykLupinaetal., author = {Seifarth, Olaf and Walczyk, Christian and Lupina, Grzegorz and Zaumseil, Peter and Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {The electronic band diagram of thin PrO2(111) / Pr-silicate buffers on Si(111) and its relevance to dielectric properties}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 136}, abstract = {Thin dielectric buffers of cubic PrO2(111) on Si(111) are ideally suited to integrate Ge onto Si by moderating the lattice mismatch between the materials. The leakage current across this dielectric buffer is strongly influenced by the electronic band diagram and defects inside the band gap. Therefore, we measured the band offsets, band gaps and defect positions by means of synchrotron radiation based photoemission spectroscopy techniques (XPS and XAS) with special emphasis on the Pr-silicate interface. In a next step we compare the spectroscopic data with information from dielectric studies, based on temperature dependent leakage current studies. We observe a close relation between dielectric properties and the electronic structure.}, language = {en} } @inproceedings{DudekLupinaKozłowskietal., author = {Dudek, Peter and Lupina, Grzegorz and Kozłowski, Grzegorz and Dabrowski, Jarek Marek and Lippert, Gunther and M{\"u}ssig, Hans-Joachim and Schmeißer, Dieter and Schroeder, Thomas}, title = {Band structure and electrical properties of MBE grown HfO2 - based alkaline earth perovskites}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 232}, abstract = {Ultra thin dielectric films (<20 nm) deposited on TiN electrodes are interesting for MIM capacitor application. High capacitance density and dielectric permittivity must be accompanied by extremely low leakage currents (10-8 A/cm2) at bias 0.5 V. To achieve such low leakage currents, high band gap and proper band alignment is required. Occupied electronic states can be probed with standard laboratory photoemission methods. Probing of unoccupied states is more challenging. Synchrotron based PES in combination with XAS forms a powerful method to study the band alignment. ASAM end station located at the U 49/2 PGM 2 beamline of BESSY II (Berlin) offers excellent conditions for performing such measurements. We investigated HfO2 - based alkaline earth perovskite - BaHfO3 with subsequent admixture of TiO2, resulting in formation of BaHf0.5Ti0.5O3 compound. The analysis of data indicates that band gap for HfO2 is similar to BaHfO3 and amounts 5.8 eV; for BaHf0.5Ti0.5O3 it decreases to 3.8 eV. We conclude that the addition of TiO2 to BaHfO3 increases significantly the dielectric permittivity but also impacts the band gap alignment. The conduction band offset shrinks, influencing the leakage current behavior.}, language = {en} } @inproceedings{PoehlmannBestleFlassigetal., author = {P{\"o}hlmann, Fiete and Bestle, Dieter and Flassig, Peter Michael and Hinz, Mich{\`e}l}, title = {Modular Automated Aerodynamic Compressor Design Process}, series = {Advances in Evolutionary and Deterministic Methods for Design, Optimiziation and Control in Engineering and Sciences}, booktitle = {Advances in Evolutionary and Deterministic Methods for Design, Optimiziation and Control in Engineering and Sciences}, editor = {Greiner, David and Galv{\`a}n, Blas and P{\`e}riaux, Jacques and Gauger, Nicolas R. and Giannakoglou, Kyriakos C. and Winter, Gabriel}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-11540-5}, doi = {10.1007/978-3-319-11541-2}, pages = {267 -- 276}, language = {en} } @inproceedings{GoryachkoBeuckertZaumseiletal., author = {Goryachko, Andriy and Beuckert, Guido and Zaumseil, Peter and Wagner, Guenter and Schmeißer, Dieter}, title = {Investigations of Pr2O3 growth modes on 4H-SiC(0001) Surfaces}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, isbn = {ISSN 0420-0195}, abstract = {The SiC is suited especially well for high power and high voltage semiconductor devices. In order to increase the reliability against electrical breakdown of metal-insulator-semiconductor (MIS) structures, one needs to use the insulator with possibly higher dielectric constant. Pr2O3 is shown to posses a much higher dielectric constant (equals 30) than traditionally used SiO2. Therefore, Pr2O3/SiC is an excellent material combination for high voltage MIS devices. The 4H-SiC(0001) substrates are characterised with scanning tunneling microscopy, while the Pr2O3 surface - with atomic force microscopy technique. We show distinct growth modes of Pr2O3 film, such as 3D and layer by layer growth. The crystalline structure and film thickness are determined by X-ray diffraction and its chemical composition by X-ray photoelectron spectroscopy. The Pr2O3 film characteristics are optimised for high-quality MIS structures in terms of lateral uniformity, low interface states density and leakage current, as well as physical integrity.}, language = {en} } @inproceedings{HendlerExtraLockanetal., author = {Hendler, Marco and Extra, Simon and Lockan, Michael and Bestle, Dieter and Flassig, Peter Michael}, title = {Compressor Design in the Context of Holistic Aero Engine Design}, series = {2017 AIAA Aviation Forum, Denver, AIAA-2017-3334, 2017}, booktitle = {2017 AIAA Aviation Forum, Denver, AIAA-2017-3334, 2017}, doi = {10.2514/6.2017-3334}, language = {en} } @misc{LutterHempelAndereretal., author = {Lutter, Anne-Helen and Hempel, Ute and Anderer, Ursula and Dieter, Peter}, title = {Biphasic influence of PGE2 on the resorption activity of osteoclast-like cells derived from human peripheral blood monocytes and mouse RAW264.7}, series = {Prostaglandins, Leukotrienes and Essential Fatty Acids}, volume = {111}, journal = {Prostaglandins, Leukotrienes and Essential Fatty Acids}, issn = {1532-2823}, doi = {10.1016/j.plefa.2016.03.017}, pages = {1 -- 7}, language = {en} } @misc{LutterHempelDieteretal., author = {Lutter, Anne-Helen and Hempel, Ute and Dieter, Peter and Anderer, Ursula}, title = {Multinuclearity is not mandatory for Bone Resorption Mononuclear Osteoclasts are able to resorbe Extracellular Bone Matrix in vitro}, series = {Bone-Tec, Munich, 2017}, journal = {Bone-Tec, Munich, 2017}, language = {en} }