Publications by authors named "Baumbach T"

In situ X-ray reciprocal space mapping was performed during the interval heating and cooling of InGaN/GaN quantum wells (QWs) grown via metal-organic vapor phase epitaxy (MOVPE). Our detailed in situ X-ray analysis enabled us to track changes in the peak intensities and radial and angular broadenings of the reflection. By simulating the radial diffraction profiles recorded during the thermal cycle treatment, we demonstrate the presence of indium concentration distributions (ICDs) in the different QWs of the heterostructure (1.

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A large number of clinical studies demonstrate that the ketogenic diet (KD) may be an effective approach to the reduction of epileptic seizures in children and adults. Such dietary therapy could also help pregnant women with epilepsy, especially since most antiseizure drugs have teratogenic action. However, there is a lack of medical data, considering the safety of using KD during gestation for the progeny.

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We derive a phase retrieval formula for propagation-based phase contrast X-ray imaging that does not require weakly attenuating objects or short propagation distances. It is directly applicable to both single- and multiple-distance scenarios. We show the validity conditions and study the error of the underlying mutual intensity approximation, which uses the common assumptions of weak phase shift variations and phase-attenuation duality.

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The hexagonal ferrite h-YbFeO grown on YSZ(111) by pulsed laser deposition is foreseen as a promising single multiferroic candidate where ferroelectricity and antiferromagnetism coexist for future applications at low temperatures. We studied in detail the microstructure as well as the temperature dependence of the magnetic properties of the devices by comparing the heterostructures grown directly on YSZ(111) (i.e.

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The morphology and crystal structure of Pt films grown by pulsed laser deposition (PLD) on yttria-stabilized zirconia (YSZ)at high temperatures = 900 °C was studied for four different film thicknesses varying between 10 and 70 nm. During the subsequent growth of the capping layer, the thermal stability of the Pt was strongly influenced by the Pt film's thickness. Furthermore, these later affected the film morphology, the crystal structure and hillocks size, and distribution during subsequent growth at = 900 °C for a long duration.

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The structure and the chemical composition of individual layers as well as of interfaces belonging to the two heterostructures M1 (BaFeO/YbFeO/YSZ) and M2 (YbFeO/BaFeO/YSZ) grown by pulsed laser deposition on yttria-stabilized zirconia (YSZ) substrates are deeply characterized by using a combination of methods such as high-resolution X-ray diffraction, transmission electron microscopy (TEM), and atomic-resolution scanning TEM with energy-dispersive X-ray spectroscopy. The temperature-dependent magnetic properties demonstrate two distinct heterostructures with different coercivity, anisotropy fields, and first anisotropy constants, which are related to the defect concentrations within the individual layers and to the degree of intermixing at the interface. The heterostructure with the stacking order BaFeO/YbFeO, i.

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We report on the fabrication of a novel design of GaAs/(In,Ga)As/GaAs radial nanowire heterostructures on a Si 111 substrate, where, for the first time, the growth of inhomogeneous shells on a lattice mismatched core results in straight nanowires instead of bent. Nanowire bending caused by axial tensile strain induced by the (In,Ga)As shell on the GaAs core is reversed by axial compressive strain caused by the GaAs outer shell on the (In,Ga)As shell. Progressive nanowire bending and reverse bending in addition to the axial strain evolution during the two processes are accessed byby x-ray diffraction.

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The development of an organism is orchestrated by the spatial and temporal expression of genes. Accurate visualisation of gene expression patterns in the context of the surrounding tissues offers a glimpse into the mechanisms that drive morphogenesis. We developed correlative light-sheet fluorescence microscopy and X-ray computed tomography approach to map gene expression patterns to the whole organism`s 3D anatomy.

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We have studied the effect of platinum underlayer for two deposited thicknesses on the microstructure, crystalline quality, morphology, chemical composition, and magnetic properties as well as magnetic domain formation of BaFeO (BaM) grown on YSZ(111) by pulsed laser deposition (PLD). We found that PLD platinum deposited with a thickness of 25 nm cannot withstand the dewetting phenomenon occurring during the subsequent BaM layer growth. A smooth and continuous Pt underlayer that possesses a sharp interface and omits the intermixing between the BaM and substrate was successfully achieved for a deposited Pt film thickness of 75 nm.

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Shot noise is a critical issue in radiographic and tomographic imaging, especially when additional constraints lead to a significant reduction of the signal-to-noise ratio. This paper presents a method for improving the quality of noisy multi-channel imaging datasets, such as data from time or energy-resolved imaging, by exploiting structural similarities between channels. To achieve that, we broaden the application domain of the Noise2Noise self-supervised denoising approach.

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Industrial biocatalysis plays an important role in the development of a sustainable economy, as enzymes can be used to synthesize an enormous range of complex molecules under environmentally friendly conditions. To further develop the field, intensive research is being conducted on process technologies for continuous flow biocatalysis in order to immobilize large quantities of enzyme biocatalysts in microstructured flow reactors under conditions that are as gentle as possible in order to realize efficient material conversions. Here, monodisperse foams consisting almost entirely of enzymes covalently linked via SpyCatcher/SpyTag conjugation are reported.

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Article Synopsis
  • Ohmic and Schottky contacts in micro- and nanoelectronics rely on metal-semiconductor bilayer systems, specifically involving elemental metals and stable metallic compounds like germanides and silicides, yet controlling their electronic properties remains complex due to unclear structural formation processes.
  • Researchers conducted a study on Pd/a-Ge bilayers with various Pd/Ge ratios, employing real-time synchrotron X-ray techniques to track microstructure changes during deposition and annealing, revealing that Pd(111) grows coherently on polycrystalline PdGe[111] with notable resistivity changes during thin film formation.
  • The study established connections between phase formation and microstructure during deposition and the solid-state reaction during annealing, showing that the
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X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) microscopy techniques are now considered popular for rapid and label-free complementary spectrochemical analysis of chemical elements and molecular systems in biological specimens. The morphological heterogeneity but also the inhomogeneities associated with the thickness/density of biological samples demonstrate challenges for the quantitative XRF microimaging. Therefore, in the present work, we proposed for the first time the application of the total absorbance under the FTIR spectra as a mass surface correction procedure for two-dimensional (2D) XRF microimaging of tissues.

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Hierarchical guidance is developed for three-dimensional (3D) nanoscale X-ray imaging, enabling identification, refinement, and tracking of regions of interest (ROIs) within specimens considerably exceeding the field of view. This opens up new possibilities for in situ investigations. Experimentally, the approach takes advantage of rapid multiscale measurements based on magnified projection microscopy featuring continuous zoom capabilities.

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Here we report on the non-uniform shell growth of InGaAs on the GaAs nanowire (NW) core by molecular beam epitaxy (MBE). The growth was realized on pre-patterned silicon substrates with the pitch size () ranging from 0.1 μm to 10 μm.

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The spatial confinement of atoms at surfaces and interfaces significantly alters the lattice dynamics of thin films, heterostructures and multilayers. Ultrathin films with high dielectric constants (high-) are of paramount interest for applications as gate layers in current and future integrated circuits. Here we report a lattice dynamics study of high- EuO films with thicknesses of 21.

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Tofu is a toolkit for processing large amounts of images and for tomographic reconstruction. Complex image processing tasks are organized as workflows of individual processing steps. The toolkit is able to reconstruct parallel and cone beam as well as tomographic and laminographic geometries.

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Atomistic processes during pulsed-laser deposition (PLD) growth influence the physical properties of the resulting films. We investigated the PLD of epitaxial layers of hexagonal LuFeO[Formula: see text] by measuring the X-ray diffraction intensity in the quasiforbidden reflection 0003 in situ during deposition. From measured X-ray diffraction intensities we determined coverages of each layer and studied their time evolution which is described by scaling exponent [Formula: see text] directly connected to the surface roughness.

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One key event in insect evolution was the development of mandibles with two joints, which allowed powerful biting but restricted their movement to a single degree of freedom. These mandibles define the Dicondylia, which constitute over 99% of all extant insect species. It was common doctrine that the dicondylic articulation of chewing mandibles remained unaltered for more than 400 million years.

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Glioblastoma multiforme (GBM) is a particularly malignant primary brain tumor. Despite enormous advances in the surgical treatment of cancer, radio- and chemotherapy, the average survival of patients suffering from this cancer does not usually exceed several months. For obvious ethical reasons, the search and testing of the new drugs and therapies of GBM cannot be carried out on humans, and for this purpose, animal models of the disease are most often used.

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Misfit strain in core-shell nanowires can be elastically released by nanowire bending in case of asymmetric shell growth around the nanowire core. In this work, we investigate the bending of GaAs nanowires during the asymmetric overgrowth by an InGaAs shell caused by avoiding substrate rotation. We observe that the nanowire bending direction depends on the nature of the substrate's oxide layer, demonstrated by Si substrates covered by native and thermal oxide layers.

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Design of novel nanowire (NW) based semiconductor devices requires deep understanding and technological control of NW growth. Therefore, quantitative feedback over the structure evolution of the NW ensemble during growth is highly desirable. We analyse and compare the methodical potential of reflection high-energy electron diffraction (RHEED) and X-ray diffraction reciprocal space imaging (XRD) for in situ growth characterization during molecular-beam epitaxy (MBE).

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Using the density functional theory, we study the structural and lattice dynamical properties of europium sesquioxide (EuO) in the cubic, trigonal, and monoclinic phases. The obtained lattice parameters and energies of the Raman modes show a good agreement with the available experimental data. The Eu-partial phonon density of states calculated for the cubic structure is compared with the nuclear inelastic scattering data obtained from a 20 nm thick EuO film deposited on a YSZ substrate.

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Most animals undergo ecological niche shifts between distinct life phases, but such shifts can result in adaptive conflicts of phenotypic traits. Metamorphosis can reduce these conflicts by breaking up trait correlations, allowing each life phase to independently adapt to its ecological niche. This process is called adaptive decoupling.

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