@inproceedings{SchmeisserMuellerHenkeletal., author = {Schmeißer, Dieter and M{\"u}ller, Sebastian and Henkel, Karsten and M{\"u}ller, Klaus and Wehner, Stefan}, title = {In-situ analysis of moving reaction fronts for the bistable CO oxidation reaction on noble metal catalyst}, series = {Extended Abstracts Book of First International Conference on Materials for Energy}, booktitle = {Extended Abstracts Book of First International Conference on Materials for Energy}, publisher = {Dechema e.V.}, address = {Frankfurt}, isbn = {978-3-89746-117-8}, pages = {S. 932}, abstract = {Experimental data on the reaction kinetics of catalytic processes are prerequisite for modeling of such reactions and their output. We investigate the CO oxidation on some noble metal catalysts, like Iridium(111) and Palladium(111) which is a bistable surface reaction. In a specific range of CO content in the feed gas islands of one or the other adsorbate nucleate and grow, which is recorded with photo electron emission microscopy (PEEM). During these transients the coverage on the surface changes from predominantly oxygen covered to predominantly CO covered resp. vice versa. But the resolution of PEEM and especially its unknown and nonlinear dependence of coverage of the two adsorbates (oxygen and CO) and image intensity make it impossible to extract the changes in coverage. On the other hand the reaction diffusion model based on the Langmuir-Hinshelwood-mechanism delivers the coverage of oxygen and carbon monoxide. The shapeand wall velocity of those islands has been connected perfectly to each other [CPL 423 (2006) 39], but not the absolute coverage and their variation during the reaction. Since the domain wall velocity is small on Iridium(111), this has opened the possibility for a detailed analysis of the changing coverage inside this domain wallutilizing synchrotron radiation and photo electron spectroscopy at BESSY II. The coverage profile of oxygen and CO inside a moving domain wall was measured for both cases using XPS spectra at O1s, C1s and the valence band during thereaction. Comparison with the reaction-diffusion-model and other catalytic surfaces, like Palladium(111) are done.}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Synchrotron radiation spectroscopy studies of ultrathin chromium films on titanium dioxide}, series = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, booktitle = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4303-1}, pages = {64 -- 68}, language = {en} } @inproceedings{MuellerSchoelzel, author = {M{\"u}ller, Sebastian and Sch{\"o}lzel, Mario}, title = {Combining Hardware and Software Based Self Repair Methods for Statically Scheduled Data Paths}, series = {2010 IEEE 25th International Symposium on Defect and Fault Tolerance in VLSI Systems (DFT 2010), Kyoto, Japan, 6 - 8 October 2010}, booktitle = {2010 IEEE 25th International Symposium on Defect and Fault Tolerance in VLSI Systems (DFT 2010), Kyoto, Japan, 6 - 8 October 2010}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-424-48447-8}, pages = {90 -- 98}, language = {en} } @inproceedings{MuellerSchoelzelVierhaus, author = {M{\"u}ller, Sebastian and Sch{\"o}lzel, Mario and Vierhaus, Heinrich Theodor}, title = {Hierarchical Self-repair in Heterogenous Multi-core Systems by Means of a Software-based Reconfiguration}, series = {VEFRE 8th Workshop on Dependability and Fault-Tolerance, Proceedings of ARCS 2012 Workshops}, booktitle = {VEFRE 8th Workshop on Dependability and Fault-Tolerance, Proceedings of ARCS 2012 Workshops}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-4673-1913-3}, pages = {7}, language = {en} } @inproceedings{MuellerSchoelzelVierhaus, author = {M{\"u}ller, Sebastian and Sch{\"o}lzel, Mario and Vierhaus, Heinrich Theodor}, title = {Towards a Graceful Degradable Multicore-System by hierarchical Handling of Hard Errors}, series = {DaRMuS 2013, Special Session on Dynamic and Reliable Multicore Systems, Hosted by 21st Euromicro PDP Conference}, booktitle = {DaRMuS 2013, Special Session on Dynamic and Reliable Multicore Systems, Hosted by 21st Euromicro PDP Conference}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-146-735-321-2}, pages = {302 -- 309}, language = {en} } @inproceedings{MuellerKoalSchoelzeletal., author = {M{\"u}ller, Sebastian and Koal, Tobias and Sch{\"o}lzel, Mario and Vierhaus, Heinrich Theodor}, title = {Timing for Virtual TMR in Logic Circuits}, series = {IOLTS 2014, 20th IEEE International On-Line Testing Symposium Hotel Cap Roig, Platja d'Aro, Catalunya, Spain July 7-9, 2014}, booktitle = {IOLTS 2014, 20th IEEE International On-Line Testing Symposium Hotel Cap Roig, Platja d'Aro, Catalunya, Spain July 7-9, 2014}, isbn = {978-1-4799-5324-0}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {The initial stages of Chromium growth on Titaniumdioxide-Investigations using synchrotron radiation}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 598}, abstract = {We investigate the interface of Cr-TiO2 during the initial stages of Cr deposition. Experiments are carried out at BESSY II (BL U49/2-PGM2). Using XPS, XAS and ResPES we obtain information about electronic structure at the interface. We confirm the results of growth studies by Christian Winde obtained by TEM-EELS. In addition, we find that Cr deposition induces two gap states which appear about 1 eV and 3 eV below EF. Using ResPES, these states can be identified as being Cr-like and Ti-like respectively. Core-level-XPS and CIS-spectra of the lower gap state indicate the existence of mainly Cr4+ at low coverage (< 1 ML). At higher coverage (≈ 2.5 ML) metallic Cr is observed as well as metallic Ti. Oxidized Cr occurs mainly as Cr3+. CIS-spectra of higher gap state show metallic behavior with both Cr- and Ti-like character. CIS-spectra of lower gap-state confirm the existence of Cr3+. Reference: Christian Winde, Herstellung und Charakterisierung von Cr Schichten auf TiO2 (110)Oberfl{\"a}chen, PhD Thesis, University of Stuttgart, 2002}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Synchrotron radiation spectroscopy studies of the initial interaction between cobalt and titanium dioxide}, 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. 652}, abstract = {Small metallic particles deposited on oxide surfaces can serve as heterogeneous catalysts, as for example TiO2 supported cobalt is a known Fischer-Tropsch-Catalyst. The goal of the presented studies is to investigate the interaction between cobalt and TiO2 in the initial step of growth by synchrotron radiation based spectroscopy. PES studies of TiO2 supported cobalt show a reduction of the oxide support, accompanied by an oxidation of the deposited material. The oxidation is not complete, but metallic cobalt is found already in the very first step of growth. Uniform decrease of both substrate PES lines indicate very weak interaction between overlayer and TiO2. An atomic multiplet calculation including charge transfer and crystal field effects is applied to simulate the experimental Co 2p XAS and XPS spectra of the oxidized component. The results allow the identification of the local coordination as well as the identification of the oxidation state of cobalt.}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Direct Observation of d2L2 Charge Transfer States in TiO2 thin films by Resonant Photoelectron Spectroscopy}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 592}, abstract = {We investigate the electronic structure of TiO2 thin films by SR-PES, NEXAFS and ResPES. The films are prepared in a combined in-situ/ex-situ process that leads to stoichiometric thin films (≈ 10 nm) in Rutile structure. We focus on ResPES at the Ti 2p edge. When the photon energy is close to the Ti 2p absorption edge we observe additional features about 13 eV below the valence band main features. These features show clear spectator auger decay at the resonance leading to d0 final state. From this, we deduce the existence of the d2L2 initial charge transfer state as this is the only possible channel that enables the corresponding spectator auger decay. These features have the same origin as the satellite structures observed in core level spectra, esp. 2p and 3p.}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Investigation of ultra-thin Chromium layers on Titanium Dioxide by resonant photoemission}, 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. 453}, abstract = {Oxide supported metal films and clusters offer interesting properties with a wide range of possible applications. In this context, Titanium Dioxide is chosen as a model substrate due to its simple electronic structure with a d0 configuration. We study the interaction of ultrathin Chromium films deposited on TiO2 film with focus on the modifications of the valence band and band gap region. Normal photoemission in bulk and surface sensitive modes as well as resonant photoemission at the Cr 2p and Ti 2p edges are used to distinguish the different Cr 3d and Ti 3d contributions to the valence band. In the initial step we find to gap states of distinct character with a sharp resonance of the Cr 3d related state at the Cr 2p edge. With increasing layer thickness we observe that this resonance extends to about 20 eV below the Fermi-Energy. Datasets of valence band spectra measured around the Cr 2p edge show 2 resonant mechanisms in this case i.e. a participator channel for the 3d state accompanied by a spectator channel at fixed kinetic energy.}, language = {en} }