TY - GEN A1 - Weißhaupt, David A1 - Sürgers, Christoph A1 - Bloos, Dominik A1 - Funk, Hannes Simon A1 - Oehme, Michael A1 - Fischer, Gerda A1 - Schubert, Markus Andreas A1 - Wenger, Christian A1 - van Slageren, Joris A1 - Fischer, Inga Anita A1 - Schulze, Jörg T1 - Lateral Mn5Ge3 spin-valve in contact with a high-mobility Ge two-dimensional hole gas T2 - Semiconductor Science and Technology N2 - Abstract Ge two-dimensional hole gases (2DHG) in strained modulation-doped quantum-wells represent a promising material platform for future spintronic applications due to their excellent spin transport properties and the theoretical possibility of efficient spin manipulation. Due to the continuous development of epitaxial growth recipes extreme high hole mobilities and low effective masses can be achieved, promising an efficient spin transport. Furthermore, the Ge 2DHG can be integrated in the well-established industrial complementary metal-oxide-semiconductor (CMOS) devices technology. However, efficient electrical spin injection into a Ge 2DHG—an essential prerequisite for the realization of spintronic devices—has not yet been demonstrated. In this work, we report the fabrication and low-temperature magnetoresistance (MR) measurements of a laterally structured Mn5Ge3/Ge 2DHG/ Mn5Ge3 device. The ferromagnetic Mn5Ge3 contacts are grown directly into the Ge quantum well by means of an interdiffusion process with a spacing of approximately 130 nm, forming a direct electrical contact between the ferromagnetic metal and the Ge 2DHG. Here, we report for the first time a clear MR signal for temperatures below 13 K possibly arising from successful spin injection into the high mobility Ge 2DHG. The results represent a step forward toward the realization of CMOS compatible spintronic devices based on a 2DHG. KW - two-dimensional hole gas Y1 - 2024 U6 - https://doi.org/10.1088/1361-6641/ad8d06 SN - 0268-1242 VL - 39 IS - 12 SP - 1 EP - 10 PB - IOP Publishing ER - TY - GEN A1 - Boch, Steffen A1 - Allan, Eric A1 - Birkhofer, Klaus A1 - Bossdorf, Oliver A1 - Blüthgen, Nico A1 - Christ-Breulmann, Sabina A1 - Diekötter, Tim A1 - Dormann, Carsten F. A1 - Gossner, Martin M. A1 - Hallmann, Christine A1 - Hemp, Andreas A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klaus, Valentin H. A1 - Klein, Alexandra M. A1 - Kleinebecker, Till A1 - Lange, Markus A1 - Müller, Jörg A1 - Nacke, Heiko A1 - Prati, Daniel A1 - Renner, Swen C. A1 - Rothenwöhrer, Christoph A1 - Schall, Peter A1 - Schulze, Ernst-Detlef A1 - Socher, Stephanie A. A1 - Tscharntke, Teja A1 - Türke, Manfred A1 - Weiner, Christiane N. A1 - Weisser, Wolfgang W. A1 - Westphal, Catrin A1 - Wolters, Volkmar A1 - Wubet, Tesfaye A1 - Fischer, Markus T1 - Extensive und jährlich wechselnde Nutzungsintensität fördert den Artenreichtum im Grünland T2 - ANLIEGEN NATUR Y1 - 2016 UR - https://www.biom.uni-freiburg.de/mitarbeiter/dormann/boch2016anliegennatur.pdf SN - 1864-0729 VL - 38 IS - 1 SP - 86 EP - 95 ER - TY - GEN A1 - Hayat, Ahsan A1 - Ratzke, Markus A1 - Alvarado Chavarin, Carlos A1 - Zöllner, Marvin Hartwig A1 - Corley-Wiciak, Agnieszka Anna A1 - Schubert, Markus Andreas A1 - Wenger, Christian A1 - Fischer, Inga Anita T1 - Structural and morphological properties of CeO2 films deposited by radio frequency magnetron sputtering for back-end-of-line integration T2 - Thin Solid Films Y1 - 2024 U6 - https://doi.org/10.1016/j.tsf.2024.140547 SN - 0040-6090 VL - 807 ER - TY - GEN A1 - Hayat, Ahsan A1 - Spirito, Davide A1 - Corley-Wiciak, Agnieszka Anna A1 - Schubert, Markus Andreas A1 - Masood, Maria A1 - Reichmann, Felix A1 - Ratzke, Markus A1 - Capellini, Giovanni A1 - Fischer, Inga Anita T1 - MBE-based growth of Sn-rich quantum wells and dots at low Sn deposition rates T2 - Materials Science in Semiconductor Processing Y1 - 2023 U6 - https://doi.org/10.1016/j.mssp.2023.107693 SN - 1873-4081 VL - 165 ER - TY - GEN A1 - Kalra, Amanpreet A1 - Alvarado Chavarin, Carlos A1 - Nitsch, Paul-Gregor A1 - Tschammer, Rudi A1 - Flege, Jan Ingo A1 - Ratzke, Markus A1 - Zoellner, Marvin Hartwig A1 - Schubert, Markus Andreas A1 - Wenger, Christian A1 - Fischer, Inga Anita T1 - Deposition of CeOₓ/SnOₓ-based thin films via RF magnetron sputtering for resistive gas sensing applications T2 - Physica B, Condensed matter N2 - Cerium oxide-tin oxide (CeOx/SnOx) thin films with varying Sn content were deposited using RF magnetron sputtering and investigated for hydrogen sensing applications. Structural, compositional, and morphological properties were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Gas sensing measurements showed effective hydrogen detection at room temperature, with the sensitivity strongly influenced by Sn content and oxygen vacancy concentration. Higher Sn concentration enhanced the sensing response, which was correlated with microstructural features obtained from AFM and EDX, as well as with the presence of Ce3+ and Ce4+ oxidation states identified by XPS. This study highlights the potential of CeOx/SnOx thin films for possible back-end-of-line integration and provides proof-of-principle for room-temperature hydrogen sensing. KW - RF magnetron sputtering KW - CeOx/SnOx thin film KW - Room temperature KW - Hydrogen sensing Y1 - 2026 U6 - https://doi.org/10.1016/j.physb.2025.418098 SN - 0921-4526 VL - 723 SP - 1 EP - 7 PB - Elsevier BV CY - Amsterdam ER - TY - GEN A1 - Zaplata, Markus K. A1 - Winter, S. A1 - Biemelt, Detlef A1 - Fischer, Annette T1 - Colonization potential of the opportunistic herb Conyza canadensis at the landscape scale in an initial catchment Y1 - 2010 ER - TY - GEN A1 - Fischer, Alfons A1 - Weiß, Sabine A1 - Wimmer, Markus A. T1 - The Tribological Difference between Biomedical Steels and CoCrMo-Alloys T2 - Journal of the Mechanical Behavior of Biomedical Materials Y1 - 2012 SN - 1878-0180 VL - 9 SP - 50 EP - 62 ER - TY - GEN A1 - Zaplata, Markus K. A1 - Winter, Susanne A1 - Biemelt, Detlef A1 - Fischer, Anton T1 - Immediate shift towards source dynamics: The pioneer species Conyza canadensis in an initial ecosystem T2 - Flora - Morphology, Distribution, Functional Ecology of Plants N2 - The aim of this study was to detect a potential temporal shift from sink to source dynamics of pioneer plants during primary succession. The study was done in an initial ecosystem, namely an artificially constructed catchment on Pleistocene sands in eastern Germany. The import and export of seeds (including soil seed bank and seed rain), the development of vegetation cover and the population size of all pioneer species were recorded in 2005–2009. The interplay between the spatial distribution of seed rain and the prevailing wind direction provide evidence that seeds of Conyza canadensis (Asteraceae) first and to a considerable amount left the developing ecosystem. A change from a sink to source dynamics was detected already in the first year of both the existence of the site and occurrence of C. canadensis individuals within the site. Population patterns at the landscape unit scale demonstrated extensive auto-correlations in the coverage of this invasive plant at first. Our results underline the pioneer traits of C. canadensis as a prolific seeder and excellent wind disperser, which enables this species to become rapidly dominant over relatively large areas. KW - colonization potential Y1 - 2011 U6 - https://doi.org/10.1016/j.flora.2011.07.001 VL - 206 IS - 11 SP - 928 EP - 934 ER - TY - GEN A1 - Zaplata, Markus K. A1 - Winter, Susanne A1 - Fischer, Anton A1 - Kollmann, Johannes A1 - Ulrich, Werner T1 - Species-driven phases and increasing structure in early-successional plant communities T2 - The American Naturalist N2 - Successional phases describe changes in ecological communities that proceed in steps rather than continuously. Despite their importance for the understanding of ecosystem development, there still exists no reliable definition of phases and no quantitative measure of phase transitions. In order to obtain these data, we investigated primary succession in an artificial catchment (6 ha) in eastern Germany over a period of 6 years. The data set consists of records of plant species and their cover values, and initial substrate properties, both from plots in a regular grid (20 m × 20 m) suitable for spatial data analysis. Community assembly was studied by analyses of species co-occurrence and nestedness. Additionally, we correlated lognormal and log series distributions of species abundance to each community. We here introduce a new general method for detection of successional phases based on the degree of transient spatial homogeneity in the study system. Spatially coherent vegetation patterns revealed non-overlapping partitions within this sequence of primary succession and were characterized as two distinct ecological phases. Patterns of species co-occurrence were increasingly less random, and hence the importance of demographic stochasticity and neutral community assembly decreased during the study period. Our findings highlight the spatial dimension of successional phases and quantify the degree of change between these steps. They are an element for advancing a more reliable terminology of ecological successions. KW - spatial analysis Y1 - 2013 U6 - https://doi.org/10.1086/668571 VL - Vol. 181 IS - 1 SP - E17 EP - E27 ER - TY - GEN A1 - Weinhardt, Lothar A1 - Fuchs, Oliver A1 - Fischer, André A1 - Weigand, Markus A1 - Meyer, Frank A1 - Benkert, Andreas A1 - Blum, Monika A1 - Bär, Marcus A1 - Pookpanratana, Sujitra A1 - Denlinger, Jonathan D. A1 - Heske, Clemens A1 - Umbach, Eberhard T1 - Site- and Symmetry-resolved Resonant X-ray Emission Study of a Highly-ordered PTCDA Thin Film T2 - The Journal of Physical Chemistry: C Y1 - 2016 U6 - https://doi.org/10.1021/acs.jpcc.5b12422 SN - 1932-7447 SN - 1932-7455 VL - 120 IS - 16 SP - 8607 EP - 8615 ER -