A5059247776- Particle physics theoretical and experimental studies
- Semiconductor materials and devices
- Metal and Thin Film Mechanics
- Semiconductor materials and interfaces
- Particle Accelerators and Free-Electron Lasers
- Particle Detector Development and Performance
- GaN-based semiconductor devices and materials
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Force Microscopy Techniques and Applications
- ZnO doping and properties
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Surface and Thin Film Phenomena
- Advanced X-ray Imaging Techniques
- X-ray Diffraction in Crystallography
- Bone Tissue Engineering Materials
- Molecular Junctions and Nanostructures
- Semiconductor Quantum Structures and Devices
- Electrospun Nanofibers in Biomedical Applications
- Organic Electronics and Photovoltaics
- Muon and positron interactions and applications
- Ion-surface interactions and analysis
- Radiation Detection and Scintillator Technologies
Karlsruhe Institute of Technology
2015-2024
Deutsches Elektronen-Synchrotron DESY
1998-2023
Roma Tre University
2019
Elettra-Sincrotrone Trieste S.C.p.A.
2019
European Synchrotron Radiation Facility
2005-2011
European Science Foundation
2005-2006
Institut de Ciència de Materials de Barcelona
2006
University of Łódź
2006
Ludwig-Maximilians-Universität München
2005
Paul Scherrer Institute
1991-2004
Results are reported from the HERMES experiment at HERA on a measurement of neutron spin structure function $g_1^n(x,Q^2)$ in deep inelastic scattering using 27.5 GeV longitudinally polarized positrons incident $^3$He internal gas target. The data cover kinematic range $0.023
Elaboration of novel biocomposites providing simultaneously both biodegradability and stimulated bone tissue repair is essential for regenerative medicine. In particular, piezoelectric are attractive because a possibility to electrically stimulate cell response. the present study, CaCO3-mineralized biodegradable scaffolds based on two polymers, poly[(R)3-hydroxybutyrate] (PHB) poly[3-hydroxybutyrate-co-3-hydroxyvalerate] (PHBV), presented. Mineralization scaffold surface carried out by in...
Extreme-ultraviolet to x-ray free-electron lasers (FELs) in operation for scientific applications are up now single-user facilities. While most FELs generate around 100 photon pulses per second, FLASH at DESY can deliver almost two orders of magnitude more this time span due its superconducting accelerator technology. This makes the facility a prime candidate realize next step FELs—dividing electron pulse trains into several FEL lines and delivering users same time. Hence, has been extended...
The incorporation of bioactive compounds onto polymer fibrous scaffolds with further control drug release kinetics is essential to improve the functionality for personalized therapy and regenerative medicine. In this study, hybrid microcapsules were prepared used as carriers, which are deposited microfiber [polycaprolactone (PCL), poly(3-hydroxybutyrate) (PHB), PHB doping conductive polyaniline (PANi) 2 wt % (PHB-PANi)]. number immobilized decreased increase in their ζ-potential due...
We report extraordinary structural order along the surface normal in thin films of organic semiconductor diindenoperylene (DIP) deposited on silicon–dioxide surfaces. Cross-sectional transmission electron microscopy (TEM), noncontact atomic force (NC–AFM), as well specular and diffuse x-ray scattering measurements were performed to characterize DIP. Individual monolayers essentially upright-standing DIP molecules could be observed TEM images indicative high order. NC–AFM showed large...
The SINDRUM II spectrometer at Paul Scherrer Institute is used in a search for coherent $\ensuremath{\mu}\ensuremath{\rightarrow}e$ conversion muonic atoms. We report on measurement lead, which resulted...
The planar organic molecule 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) deposited on Ag(111) has been used as a model system for molecular-beam epitaxy (OMBE). crystal structure and morphology of thin films in the range $50--200\mathrm{\AA{}}$ have examined detail function growth parameters by x-ray diffraction noncontact atomic force microscopy. Evidence coexistence $\ensuremath{\alpha}$- $\ensuremath{\beta}$-like structures found variety conditions. A temperature-dependent...
We report on the preparation of high performance field-effect transistors (FETs) based large areas aligned films a TTF derivative, namely, tetrakis-(octadecylthio)-tetrathiafulvalene (TTF-4SC18). TTF-4SC18 assembles into one-dimensional stacks in which long alkyl chains promote intermolecular π−π overlapping due to their extremely closely packed nature. The were prepared from solution by zone-casting, simple technique that does not require use preoriented substrates. characterized AFM and...
We present a real-time X-ray scattering study of the growth modes in organic molecular-beam epitaxy. have studied model system 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) on Ag(111) and find temperature-dependent transition from layer-by-layer to islanding. The smears out for low substrate temperatures, T, implying that degree wetting layer decreases with decreasing T. This behavior has been analyzed quantitatively reproduced by kinetic Monte Carlo simulations. implications...
Residual biomass shows potential to be used as a feedstock for fast pyrolysis bio-oil production energetic and chemical use. Although environmentally advantageous, further catalytic upgrading is required in order increase the stability, by reducing reactive compounds, functional oxygen-containing groups water content. However, bio-oils may separate fractions either spontaneously after ageing or fractionated condensation. Therefore effects of on different (FPBO) obtained from commercially...
The thermal stability and dewetting effects of crystalline organic thin films on inorganic substrates have been investigated for a model system epitaxy, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) Ag(111). deposited under variety growth conditions annealed stepwise studied by in situ x-ray diffraction noncontact atomic force microscopy. It has found that comparatively smooth at temperatures Tg≲350 K are metastable, while Tg≳350 stable against annealing time scale several hours....
A portable UHV molecular beam deposition system has been developed for synthesis, in situ, and real-time x-ray diffraction measurements of organic thin films, multilayers, superlattices. The optimized small size, while still incorporating full features necessary to achieve film growth under epitaxy (MBE) conditions. It can be used independently growth, or it transported mounted on standard diffractometers. Additionally, docked a stationary multipurpose MBE sample transfer, thus permitting...
Crystals with cylindrical symmetry, not existing in nature, are mimicked by the roll-up of single-crystalline and highly strained semiconductor bilayers. Exploiting this, local structure such individual rolled-up nanotubes is locally probed quantified nondestructively x-ray microbeam diffraction. A comparison to simulations, based on minimization elastic energy, allows us determine layer thicknesses lattice parameter distributions within strongly curved
In this article, we combine diffuse x-ray scattering with a Monte Carlo simulation method for the determination of dislocation density in thin heteroepitaxial layers. As model, consider GaN epitaxial layers containing threading dislocations perpendicular to surface. The densities particular types following from comparison measured and simulated distributions diffusely scattered intensity are compared determined by etching. A good agreement was found.
In this paper we present a concept for microfluidic chamber optimized x-ray reflectivity studies at solid-liquid interfaces. Experiments of kind are usually considerably limited by strong beam attenuation due to interactions with the aqueous environment. First experiments synchrotron sources using supported model membranes showed that setup yields very effective solution minimizing background scattering and absorption, which often accompanied radiation damage biological samples....
Supported lipid membranes constitute one of the most important model systems for cell membranes. The properties supported by hydrophobic solid polymer cyclic olefin copolymer (COC) were investigated. Lipid layers consisting varying amounts 1,2-dioleoyl-3-trimethylammonium propane (DOTAP, cationic) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC, neutral) prepared vesicle fusion solvent exchange compared. All mixtures coated COC surface homogeneously forming a fluid membrane as verified...
The results of an x-ray study on freestanding, self-assembled $\mathrm{In}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ quantum dots grown by molecular beam epitaxy are presented. studied samples cover the range from statistically distributed single to dot bimolecules, and finally quadmolecules. diffraction data obtained in grazing incidence geometry, have been analyzed using isostrain model. An extended version model has developed, including lateral arrangement within a molecule superposition...
We depict the use of x-ray diffraction as a tool to directly probe strain status in rolled-up semiconductor tubes. By employing continuum elasticity theory and simple model, we are able simulate quantitatively relaxation perfect crystalline III-V bilayers multilayers well layers with dislocations. The reduction local elastic energy is evaluated for each case. Limitations technique theoretical model discussed detail.