@misc{PożarowskaPleinesEwertetal., author = {Pożarowska, Emilia and Pleines, Linus and Ewert, Moritz and Prieto, Mauricio J. and Tănase, Liviu Christian and Souza Caldas, Lucas de and Tiwari, Aarti and Schmidt, Thomas and Falta, Jens and Krasovskii, Eugene and Morales, Carlos and Flege, Jan Ingo}, title = {Preparation and stability of the hexagonal phase of samarium oxide on Ru(0001)}, series = {Ultramicroscopy}, volume = {250}, journal = {Ultramicroscopy}, issn = {0304-3991}, doi = {10.1016/j.ultramic.2023.113755}, abstract = {We have used low-energy electron microscopy (LEEM), micro-illumination low-energy electron diffraction (µLEED) supported by ab initio calculations, and X-ray absorption spectroscopy (XAS) to investigate in-situ and in real-time the structural properties of Sm2O3 deposits grown on Ru(0001), a rare-earth metal oxide model catalyst. Our results show that samarium oxide grows in a hexagonal A-Sm2O3 phase on Ru(0001), exhibiting a (0001) oriented-top facet and (113) side facets. Upon annealing, a structural transition from the hexagonal to cubic phase occurs, in which the Sm cations exhibit the +3 oxidation state. The unexpected initial growth in the A-Sm2O3 hexagonal phase and its gradual transition to a mixture with cubic C-Sm2O3 showcases the complexity of the system and the critical role of the substrate in the stabilization of the hexagonal phase, which was previously reported only at high pressures and temperatures for bulk samaria. Besides, these results highlight the potential interactions that Sm could have with other catalytic compounds with respect to the here gathered insights on the preparation conditions and the specific compounds with which it interacts.}, language = {en} } @misc{HallSchmidtWaggeetal., author = {Hall, Braeden and Schmidt, Kathleen and Wagge, Jordan and Lewis, Savannah C. and Weissgerber, Sophia C. and Kiunke, Felix and Pfuhl, Gerit and Stieger, Stefan and Tran, Ulrich S. and Barzykowski, Krystian and Bogatyreva, Natalia and Kowal, Marta and Massar, KarlIJn and Pernerstofer, Felizitas and Sorokowski, Piotr and Voracek, Martin and Chartier, Christopher R. and Brandt, Mark J. and Grahe, Jon E. and {\"O}zdoğru, Asil A. and Andreychik, Michael R. and Chen, Sau-Chin and Evans, Thomas R. and Hautekiet, Caro and IJzerman, Hans and Kačm{\´a}r, Pavol and Krafnick, Anthony J. and Musser, Erica D. and Vergauwe, Evie and Werner, Kaitlyn M. and Aczel, Balazs and Arriaga, Patr{\´i}cia and Batres, Carlota and Beaudry, Jennifer L. and Cova, Florian and Ďurbisov{\´a}, Simona and Cramblet Alvarez, Leslie D. and Feldman, Gilad and Godbersen, Hendrik and Gottfried, Jaroslav and Haeffel, Gerald J. and Hartanto, Andree and Isloi, Chris and McFall, Joseph P. and Milyavskaya, Marina and Moreau, David and Nos{\´a}ľov{\´a}, Ester and Papaioannou, Kostas and Ruiz-Fernandez, Susana and Schr{\"o}tter, Jana and Storage, Daniel and Vezirian, Kevin and Volz, Leonhard and Weisberg, Yanna J. and Xiao, Qinyu and Awlia, Dana and Branit, Hannah W. and Dunn, Megan R. and Groyecka-Bernard, Agata and Haneda, Ricky and Kielinska, Julita and Kolle, Caroline and Lubomski, Paweł and Miller, Alexys M. and M{\ae}kel{\ae}, Martin J. and Pantazi, Mytro and Ribeiro, Rafael R. and Ross, Robert M. and Sorokowska, Agnieszka and Aberson, Christopher L. and Vassiliou, Xanthippi Alexi and Baker, Bradley J. and Bognar, Miklos and Cong, Chin Wen and Danvers, Alex F. and Davis, William E. and Dranseika, Vilius and Dumbravă, Andrei and Farmer, Harry and Field, Andy P. and Forscher, Patrick S. and Graton, Aur{\´e}lien and Hajdu, Nandor and Howlett, Peter A. and Kabut, Radosław and Larsen, Emmett M. and Lee, Sean T. H. and Legate, Nicole and Levitan, Carmel A. and Levy, Neil and Lu, Jackson G. and Misiak, Michał and Morariu, Roxana E. and Novak, Jennifer and Pronizius, Ekaterina and Prusova, Irina and Rathnayake, Athulya S. and Romanova, Marina O. and R{\"o}er, Jan P. and Sampaio, Waldir M. and Schild, Christoph and Schulte-Mecklenbeck, Michael and Stephen, Ian D. and Szecsi, Peter and Takacs, Elizabeth and Teeter, Julia N. and Thiele-Evans, Elian H. and Valeiro-Paterlini, Julia and Vilares, Iris and Villafana, Louise and Wang, Ke and Wu, Raymond and {\´A}lvarez-Solas, Sara and Moshontz, Hannah and Buchanan, Erin M.}, title = {Registered Replication Report: A Large Multilab Cross-Cultural Conceptual Replication of Turri et al. (2015)}, series = {Advances in Methods and Practices in Psychological Science}, volume = {7}, journal = {Advances in Methods and Practices in Psychological Science}, number = {4}, publisher = {SAGE Publications}, issn = {2515-2459}, doi = {10.1177/25152459241267902}, pages = {1 -- 38}, language = {en} } @misc{TschammerBussPożarowskaetal., author = {Tschammer, Rudi and Buß, Lars and Pożarowska, Emilia and Morales, Carlos and Senanayake, Sanjaya D. and Prieto, Mauricio J. and Tănase, Liviu C. and de Souza Caldas, Lucas and Tiwari, Aarti and Schmidt, Thomas and Ni{\~n}o, Miguel A. and Foerster, Michael and Falta, Jens and Flege, Jan Ingo}, title = {High-temperature growth of CeOx on Au(111) and behavior under reducing and oxidizing conditions}, series = {The journal of physical chemistry C}, volume = {129}, journal = {The journal of physical chemistry C}, number = {7}, publisher = {American Chemical Society (ACS)}, address = {Washington, DC}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.4c08072}, pages = {3583 -- 3594}, abstract = {Inverse oxide-metal model catalysts can show superior activity and selectivity compared with the traditional supported metal-oxide architecture, commonly attributed to the synergistic overlayer-support interaction. We have investigated the growth and redox properties of ceria nanoislands grown on Au(111) between 700 and 890 °C, which yields the CeO2-Au(111) model catalyst system. We have observed a distinct correlation between deposition temperature, structural order, and oxide composition through low-energy electron microscopy, low-energy electron diffraction, intensity-voltage curves, and X-ray absorption spectroscopy. Improved structural order and thermal stability of the oxide have been achieved by increasing the oxygen chemical potential at the substrate surface using reactive oxygen (O/O2) instead of molecular O2 during growth. In situ characterization under reducing (H2) and oxidizing atmospheres (O2, CO2) indicates an irreversible loss of structural order and redox activity at high reduction temperatures, while moderate temperatures result in partial decomposition of the ceria nanoislands (Ce3+/Ce4+) to metallic cerium (Ce0). The weak interaction between Au(111) and CeOx would facilitate its reduction to the Ce0 metallic state, especially considering the comparatively strong interaction between Ce0 and Au0. Besides, the higher reactivity of atomic oxygen promotes a stronger interaction between the gold and oxide islands during the nucleation process, explaining the improved stability. Thus, we propose that by driving the nucleation and growth of the ceria/Au system in a highly oxidizing regime, novel chemical properties can be obtained.}, language = {en} } @misc{MubarakPhungArzetal., author = {Mubarak, Faisal Ali and Phung, Gia Ngoc and Arz, Uwe and Haddadi, Kamel and Roch-Jeune, Isabelle and Ducournau, Guillaume and Flisgen, Thomas and Doerner, Ralf and Allal, Djamel and Jayasankar, Divya and Stake, Jan and Schmidt, Robin and Fisher, Gavin and Ridler, Nick M. and Shang, Xiaobang}, title = {An interlaboratory comparison of on-wafer S-parameter measurements up to 1.1 THz}, series = {IEEE Transactions on Terahertz Science and Technology}, volume = {15}, journal = {IEEE Transactions on Terahertz Science and Technology}, number = {3}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, address = {New York, NY}, issn = {2156-3446}, doi = {10.1109/TTHZ.2025.3537461}, pages = {344 -- 358}, abstract = {This article reports on an interlaboratory measurement comparison involving on-wafer S-parameter measurements from 10 GHz to 1.1 THz. Seven laboratories are involved, and each participant has measured an individual reference substrate fabricated from a high-resistivity silicon wafer in the same batch. One- and two-port co-planar waveguide (CPW) structures are designed, simulated, and fabricated. The measurements from 10 GHz to 1.1 THz, extending across six frequency bands, are conducted using different equipment in terms of vendors and specifications (e.g., probe pitch size). Despite such differences, this interlaboratory study has shown a generally good agreement between results from different participants when uncertainties are considered. The comparison with simulated reference values demonstrates agreement within 0.08 for |S11| and 2 dB for |S21| measurements of matched devices up to 1.1 THz. The measurement comparison demonstrates the need for a standardized measurement approach and, with that, a potential to achieve accurate on-wafer CPW measurements up to THz frequencies, underpinning the development of integrated circuits for such high frequencies.}, language = {en} } @misc{BursyBawamiaFlisgenetal., author = {Bursy, Marcel and Bawamia, Ahmad and Flisgen, Thomas and Goossen-Schmidt, Nora and Luplow, Charleen and Schiemangk, Max and Tyborski, Christoph and Wicht, Andreas}, title = {Miniaturised optical isolators for realising micro-integrated photonic modules in quantum technology applications}, series = {Conference on Lasers and Electro-Optics Europe \& European Quantum Electronics Conference (CLEO/Europe-EQEC), 23-27 June 2025, Munich, Germany}, journal = {Conference on Lasers and Electro-Optics Europe \& European Quantum Electronics Conference (CLEO/Europe-EQEC), 23-27 June 2025, Munich, Germany}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, address = {New York, NY}, doi = {10.1109/CLEO/Europe-EQEC65582.2025.11109710}, pages = {1 -- 1}, abstract = {At the Ferdinand-Braun-Institut (FBH), we have been using our proven hybrid micro-integration technology for more than a decade to realise ultra-compact photonic modules for quantum applications [1]. Our latest innovations: Next-generation laser modules covering an extended wavelength range [2], and newly developed light control units for use in optical atomic clocks [3].}, language = {en} } @misc{BraudBussMerteetal., author = {Braud, Nicolas and Buß, Lars and Merte, Lindsay Richard and Wallander, Harald and Krisponeit, Jon-Olaf and Schmidt, Thomas and Lundgren, Edvin and Flege, Jan Ingo and Falta, Jens}, title = {Growth and oxidation of ultra-thin Pt-Sn layers on Pt(111) by molecular and atomic oxygen}, series = {Ultramicroscopy}, volume = {278}, journal = {Ultramicroscopy}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {0304-3991}, doi = {10.1016/j.ultramic.2025.114243}, pages = {1 -- 11}, abstract = {The preparation of ultra-thin PtSn-alloyed layers by molecular beam epitaxy was studied using low-energy electron microscopy (LEEM) and micro-diffraction (-LEED). Deposition at a sample temperature of 435 °C initially results in the formation of a PtSn/Pt(111) layer showing a (2 × 2) reconstruction. With continued Sn deposition, a PtSn/Pt(111) layer develops, showing a ()R30° reconstruction. An ultra-thin tin oxide was formed from the (2 × 2) surface by exposure to molecular oxygen at temperatures of 500 °C and 590 °C, respectively. LEED shows the evolution of a new surface structure, which could be identified as an incommensurate rectangular reconstruction with lattice parameters of a = (6.4 ± 0.1) {\AA} and b = (8.6 ± 0.1) {\AA} present in three domains rotated by 120° with respect to each other. This structure can be related to the zigzag reconstructions found for similar ultra-thin oxide systems. Contrarily, the ()R30° structure showed no oxide formation even after extensive exposure to molecular oxygen. The usage of atomic oxygen, however, allows for oxidation of this surface and the growth of thicker oxides on both types of overlayers. At 500 °C this process is accompanied by substantial roughening of the surface.}, language = {en} } @misc{PożarowskaPleinesPrietoetal., author = {Pożarowska, Emilia and Pleines, Linus and Prieto, Mauricio J. and Tănase, Liviu C. and de Souza Caldas, Lucas and Tiwari, Aarti and Schmidt, Thomas and Falta, Jens and Morales, Carlos and Flege, Jan Ingo}, title = {The relationship between Sm alloying and structure sensitivity of ceria(111)- and (100)-oriented nanoislands on Cu(111)}, series = {Physical chemistry, chemical physics}, volume = {27}, journal = {Physical chemistry, chemical physics}, number = {29}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/D5CP01171J}, pages = {15691 -- 15703}, abstract = {We have investigated the complex dynamics of samarium deposition on ceria islands of different orientations, namely (111) and (100), grown side by side on a Cu(111) single-crystal substrate, followed by post-oxidation and annealing under ultra-high vacuum conditions. Only the (100)-oriented ceria islands undergo substantial initial reduction upon samarium deposition at 740 K via a pathway similar to the strong Ce-ceria interfacial interaction, while the (111)-oriented islands remain in the Ce4+ oxidation state. This remarkable structure sensitivity is explained by the different energies required for oxygen vacancy formation for both oxide orientations. Subsequent mild re-oxidation with O2 results in the complete recovery of the Ce4+ oxidation state in the (100)-oriented islands, indicating the complete healing of oxygen vacancies. In contrast, extended annealing at moderate temperatures likely induces persistent samarium incorporation into the cerium oxide matrix. Our results provide new insights into the complex structure-activity relationships in mixed rare-earth metal oxide systems and have promising implications for optimizing catalytic reactions over such compounds in reducing environments.}, language = {en} } @misc{AckermannPeilQuarzetal., author = {Ackermann, G. and Peil, M. and Quarz, C. and Schmidt, A. and Halaczkiewicz, M. and Thomas, A. D. and Stegm{\"u}ller, S. and Richling, E. and Manolikakes, G. and Christmann, M. and K{\"u}pper, Jan-Heiner and Schrenk, D. and Fahrer, J.}, title = {Molecular dosimetry of estragole and 1′-hydroxyestragole-induced DNA adduct formation, clastogenicity and cytotoxicity in human liver cell models}, series = {Archives of toxicology}, volume = {99}, journal = {Archives of toxicology}, number = {9}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {0340-5761}, doi = {10.1007/s00204-025-04084-2}, pages = {3769 -- 3785}, abstract = {The phenylpropene estragole (ES) is found in essential oils of herbs and spices, such as bitter fennel and basil. Humans are exposed to ES through the diet and phytomedicines. After its absorption, ES undergoes metabolic activation by CYP1A2 and SULT1A1 in the liver, which can give rise to DNA adducts and hepatocarcinogenesis. Until now, quantitative genotoxicity data for ES in human liver cells are scarce, correlating DNA adduct levels with critical effects such as clastogenicity. Here, we used human HepG2 and HepG2-CYP1A2 cells as well as primary human hepatocytes (PHH) to study the genotoxic, clastogenic and cytotoxic potential of ES and its crucial metabolite 1′-hydroxyestragole (1′OH-ES). In addition, primary rat hepatocytes (PRH) were used for selected endpoints. Treatment of HepG2-CYP1A2 cells with ES (0-2 mM) led to the concentration-dependent formation of E3′- N 2 -dG adducts. Apart from a moderate γH2AX induction, neither p53 accumulation nor cytotoxicity was observed. However, clastogenicity was demonstrated at ES concentrations ≥ 1 mM. Incubation of HepG2 cells with 1′OH-ES (0—35 µM) led to 10-50-fold higher E3′- N 2 -dG adduct levels compared to equimolar ES concentrations. Furthermore, 1′OH-ES caused γH2AX formation, p53 accumulation and cytotoxicity, which was confirmed in PHH. In agreement, 1′OH-ES induced clastogenicity at concentrations ≥ 25 µM. Molecular dosimetry revealed that a certain E3′- N 2 -dG adduct level is required to trigger clastogenicity and cytotoxicity. This was confirmed by Benchmark Concentration (BMC) modelling, showing that the BMC for clastogenicity is 12-17-fold higher than the respective BMC for DNA adduct formation. Our data indicate that a threshold level of DNA adducts is required, both in rat and human liver cells, to trigger markers of clastogenicity. These levels are unlikely to be reached in humans following chronic ES exposure through phytomedicines or the diet.}, language = {en} }