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 -