@inproceedings{IsraelMuellerRachowetal., author = {Israel, Johannes and M{\"u}ller, Klaus and Rachow, Fabian and Beuckert, Guido and Schmeißer, Dieter}, title = {Reaction kinetics of the Sabatier Reaction in a demonstration plant}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {We currently build up a demonstration plant for the direct catalytic conversion of CO2 into methane according to the Sabatier reaction CO2+4H2→CH4+2H2O. We have already reached conversion rates higher than 90\% and a selectivity close to unity in our laboratory experiments with NiO based catalysts. A good long term stability was obtained with a reactant gas flow density of 0.8 l/min cm2· at 350∘C. We will study the process now on a larger scale with a factor 10000. The process is controlled via mass flow controllers with a throughput of 20m3/h H2 and 5m3/h CO2 at an inlet gas pressure of up to 15 bar, the temperature is regulated by a PID multichannel controller. As water is a by-product we use an efficient cooling trap for its separation form the obtained methane. The reaction products are analyzed by a quadrupole mass spectrometer under reaction conditions. We start our experiments in using clean CO2 and H2. Later experiments will involve industrial quality (oxy-fuel) conditions also. Goal of this project is to determine the performance of the catalytic process under conditions which enable an industrial implementation in energy storage concepts. In this contribution we report of the design of a demonstration plant and on first experiments concerning the kinetics within the system.}, 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{DomaradzkiSchmeisserKaczmareketal., author = {Domaradzki, Jarosław and Schmeißer, Dieter and Kaczmarek, Danuta and Beuckert, Guido and Prociow, E. L. and Borkowska, Angnieszka and Kudrawiec, Robert and Misiewicz, J.}, title = {Characterization of Nanocrystalline TiO2 - HfO2 Thin Films Prepared by Low Pressure Hot Target Reactive Magnetron Sputtering}, language = {en} } @article{DomaradzkiKaczmarekSchmeisseretal., author = {Domaradzki, Jarosław and Kaczmarek, Danuta and Schmeißer, Dieter and Beuckert, Guido}, title = {Microstructure and Optical Properties of TiO2 Thin Films Prepared by Low Pressure Hot Target Reactive Magnetron Sputtering}, language = {en} } @article{GoryachkoPaloumpaBeuckertetal., author = {Goryachko, Andriy and Paloumpa, Ioanna and Beuckert, Guido and Burkov, Yevgen and Schmeißer, Dieter}, title = {The Interaction of Pr2O3 with 4H-SiC(0001)surface}, series = {Physica status solidi / C}, volume = {1}, journal = {Physica status solidi / C}, number = {2}, issn = {1610-1634}, pages = {265 -- 268}, abstract = {Praseodymium oxide (Pr2O3) as a hetero-oxide on SiC(0001) represents a promising semiconductor / high-K dielectric material combination. We prepared thin films (<3 nm) of Pr2O3 on 4H-SiC(0001) surfaces by a wet chemical process involving aqueous solutions of Pr(NO3)3. Synchrotron radiation photoelectron spectroscopy (SR-PES) is used to study the chemical composition of these films after deposition and annealing in 300-900 \%B0C range. The Si2p and C1s core level emissions are analysed in detail and reveal that praseodymium-silicate is formed at the interface. Our data are compared to corresponding studies of the Pr2O3 interaction with Si(001) surfaces.}, language = {en} } @inproceedings{HoffmannMikaloBatcheloretal., author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Batchelor, David R. and Beuckert, Guido and Schmeißer, Dieter and Kittler, Martin and Ourmazd, A. and Lewerenz, Hans-Joachim}, title = {Solare Energieumwandlung in d{\"u}nnen Schichten}, language = {de} } @incollection{SchmeisserHoffmannBeuckert, author = {Schmeißer, Dieter and Hoffmann, Patrick and Beuckert, Guido}, title = {Electronic Properties of the Interface Formed by Pr2o3 Growth on Si(001), Si(111)and SiC(0001) Surfaces}, editor = {Zschech, Ehrenfried and Whelan, Caroline}, language = {en} }