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ABSTRACT: Understanding the macroscopic physical and mechanical properties of poly(p-phenylene terephthalamide) (PpTA) fibres as a function of temperature requires an understanding of how temperature influences
its microscopic structure. This study investigates lattice distortions in single PpTA fibres using the high brilliance of
a synchrotron radiation microbeam. Lattice distortions are studied over a temperature range of 110–350K and the influence
of tensile deformation is also considered. The results reveal linear thermal expansion behaviour for all unit cell axes, in
general agreement with literature. Expansion/contraction is greatest along the [100] direction whilst being reduced along
[010] by inter-chain hydrogen bonding. During macroscopic deformation, longitudinal crystal strain dominates with respect
to axial lattice distortions induced by temperature changes. There is only a small change in the [100] coefficient of thermal
expansion, with the [010] and [001] directions being largely unaffected.
Journal of Materials Science 04/2012; 44(18):4806-4813. · 2.02 Impact Factor
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ABSTRACT: Coherent X-ray nanodiffraction was applied to investigate single GaAs nanowires. Using the nanofocus hard X-ray setup at ID13 of the ESRF, the diffraction signal from isolated nanowires was measured. The diffraction patterns were recorded for different rotations of the sample. These diffraction patterns were then combined to yield three-dimensional information around a Wurzite [101] Bragg peak.
Physica Status Solidi (A) Applications and Materials 10/2011; 208(11):2495 - 2498. · 1.46 Impact Factor
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ABSTRACT: In(Ga)As quantum dots, which laterally self-assemble into quantum dot molecules, have been studied by scanning x-ray nanodiffraction, finite element calculations and subsequent kinematical diffraction simulations. X-ray beam sizes of 100 nm enable small scattering volumes comparable to the object size at extremely high local flux densities ( ≈ 104 photons nm−2 s−1). By that bulk contributions to the scattering are effectively reduced. Area maps of various individual quantum dot molecules have been measured, whereas the diffraction patterns therein reveal spatially resolved information about the inter quantum dot position correlation function.
Applied Physics Letters 05/2011; 98(21):213105-213105-3. · 3.84 Impact Factor
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P Müller-Buschbaum,
D Magerl,
R Hengstler,
J-F Moulin,
V Körstgens,
A Diethert,
J Perlich,
S V Roth, M Burghammer,
C Riekel,
M Gross,
F Varnik,
P Uhlmann,
M Stamm,
J M Feldkamp,
C G Schroer
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ABSTRACT: The structure and flow of droplets on solid surfaces is investigated with imaging and scattering techniques and compared to simulations. To access nanostructures at the liquid-solid interface advanced scattering techniques such as grazing incidence small-angle x-ray scattering (GISAXS) with micro- and nanometer-sized beams, GISAXS and in situ imaging ellipsometry and GISAXS tomography are used. Using gold nanoparticle suspensions, structures observed in the wetting area due to deposition are probed in situ during the drying of the droplets. After drying, nanostructures in the wetting area and inside the dried droplets are monitored. In addition to drying, a macroscopic movement of droplets is caused by body forces acting on an inclined substrate. The complexity of the solid surfaces is increased from simple silicon substrates to binary polymer brushes, which undergo a switching due to the liquid in the droplet. Nanostructures introduced in the polymer brush due to the movement of droplets are observed.
Journal of Physics Condensed Matter 05/2011; 23(18):184111. · 2.55 Impact Factor
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A Schropp,
P Boye,
A Goldschmidt,
S Hönig,
R Hoppe,
J Patommel,
C Rakete,
D Samberg,
S Stephan,
S Schöder, M Burghammer,
C G Schroer
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ABSTRACT: We used hard X-ray scanning microscopy with ptychographic coherent diffraction contrast to image a front-end processed passivated microchip fabricated in 80 nm technology. No sample preparation was needed to image buried interconnects and contact layers with a spatial resolution of slightly better than 40 nm. The phase shift in the sample is obtained quantitatively. With the additional knowledge of the elemental composition determined in parallel by X-ray fluorescence mapping, quantitative information about specific nanostructures is obtained. A significant enhancement in signal-to-noise ratio and spatial resolution is achieved compared to conventional hard X-ray scanning microscopy.
Journal of Microscopy 01/2011; 241(1):9-12. · 1.63 Impact Factor
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ABSTRACT: X-ray radiation damage propagation is explored for hydrated starch granules in order to reduce the step resolution in raster-microdiffraction experiments to the nanometre range. Radiation damage was induced by synchrotron radiation microbeams of 5, 1 and 0.3 µm size with ∼0.1 nm wavelength in B-type potato, Canna edulis and Phajus grandifolius starch granules. A total loss of crystallinity of granules immersed in water was found at a dose of ∼1.3 photons nm(-3). The temperature dependence of radiation damage suggests that primary radiation damage prevails up to about 120 K while secondary radiation damage becomes effective at higher temperatures. Primary radiation damage remains confined to the beam track at 100 K. Propagation of radiation damage beyond the beam track at room temperature is assumed to be due to reactive species generated principally by water radiolysis induced by photoelectrons. By careful dose selection during data collection, raster scans with 500 nm step-resolution could be performed for granules immersed in water.
Journal of Synchrotron Radiation 11/2010; 17(6):743-50. · 2.73 Impact Factor
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C. Floss,
C. Allen,
S. Armes,
S. Bajt,
A. Ball,
R. Bastien,
H. Bechtel,
J. Borg,
F. E. Brenker,
J. C. Bridges, [......],
M. Trieloff,
J. Trigo-Rodriguez,
P. Tsou,
A. Tsuchiyama,
T. Tyliczszak,
B. Vekemans,
L. Vincze,
J. Warren,
A. J. Westphal,
M. E. Zolensky
Meteoritics and Planetary Science Supplement. 08/2010; 73:5270.
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J. Leitner,
C. Allen,
S. Armes,
S. Bajt,
A. Ball,
R. Bastien,
H. Bechtel,
J. Borg,
F. E. Brenker,
J. C. Bridges, [......],
M. Trieloff,
J. Trigo-Rodriguez,
P. Tsou,
A. Tsuchiyama,
T. Tyliczszak,
B. Vekemans,
L. Vincze,
J. Warren,
A. J. Westphal,
M. E. Zolensky
Meteoritics and Planetary Science Supplement. 08/2010; 73:5292.
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A. J. Westphal,
A. Allbrink,
C. Allen,
S. Bajt,
R. Bastien,
H. Bechtel,
P. Bleuet,
J. Borg,
S. Bowker,
F. Brenker, [......],
M. Trieloff,
P. Tsou,
A. Tsuchiyama,
T. Tyliczszak,
B. Vekemans,
L. Vincze,
J. Warren,
T. Yahnke,
D. Zevin,
M. E. Zolensky
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ABSTRACT: Here we describe the critical role that synchrotron X‐ray and infrared microprobes are playing in the search for interstellar dust in the Stardust Interstellar Dust Collector (SIDC). The samples under examination are submicron particles trapped in low‐density aerogel. We have found that the spatial resolution, energy range, and flux capabilities of the FTIR beamlines 1.4.3, ALS, and U2B, NSLS; the XRF microprobes ID13 and ID22NI, ESRF and 2‐ID‐D, APS; and the STXM beamline 11.0.2, ALS are ideally suited for studying these tiny returned samples. Using nondestructive, coordinated analyses at these microprobes, we have been able to eliminate most candidates as likely samples of interstellar dust. This in itself is a major accomplishment, since the analysis of these tiny samples is technically extremely challenging.
AIP Conference Proceedings. 04/2010; 1221(1):131-138.
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ABSTRACT: Individual self-assembled SiGe/Si(001) dot molecules were investigated by scanning x-ray nanodiffraction with a beam size of 250 nm in diameter (full width at half maximum). The samples contain dot molecules with either one, two, three, or four dots. Different azimuthal configurations were measured and compared with simulated diffraction patterns. We have combined finite element calculations, kinematic scattering simulations, and experimental measurements to obtain information about lateral positional correlation as well as strain and germanium content within individual dot molecules.
Applied Physics Letters 04/2010; · 3.84 Impact Factor
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C.G. Schroer,
P. Boye,
J.M. Feldkamp,
J. Patommel,
A. Schropp,
D. Samberg,
S. Stephan, M. Burghammer,
S Schöder,
C Riekel,
B. Lengeler,
G. Falkenberg,
G. Wellenreuther,
M. Kuhlmann,
R. Frahm,
D Lützenkirchen-Hecht,
W.H. Schroeder
Acta Physica Polonica Series a 03/2010; 117(2):357-368. · 0.44 Impact Factor
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ABSTRACT: A one-dimensional silver (Ag) nanoparticle gradient layer is prepared from an aqueous colloidal solution upon a polystyrene (PS) coated silicon (Si) substrate. For preparation two walls of different wettability are used. The 40 nm PS-layer exhibits a locally constant film thickness due to the strong roughness correlation with the underlying Si-substrate and is less wettable as compared to the glass plate placed above. The Ag nanoparticles have a triangular prism-like shape. The structural characterization of the obtained complex gradient formed by drying is performed with microbeam grazing incidence small-angle x-ray scattering based on compound refractive lenses. Due to the adsorption from aqueous solution in the selective geometry a double gradient type structure defined by two areas with characteristic lateral lengths and a cross-over regime between both is observed.
Journal of Physics Condensed Matter 07/2009; 21(26):264012. · 2.55 Impact Factor
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ABSTRACT: Instrumentation, data analysis, radiation damage, and related issues of synchrotron radiation micro- and nanodiffraction techniques
applied to soft condensed matter science are reviewed in this chapter. The current instrumental capabilities at the ESRF-ID13
beamline provide beam sizes from a few microns into the range of 100 nm. A further reduction to about 30 nm can be expected.
The reduction of beam size is accompanied by an increase in beam divergence, which limits the accessible lower Q-limit as
compared to SAXS cameras with optimized resolution due to low-divergence beams. The availability of recursive data reduction
routines allows the extraction of structural information from large 2D detector data sets.
06/2009: pages 91-104;
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J.B. Pelka,
R. Sobierajski,
D. Klinger,
W. Paszkowicz,
J. Krzywinski,
M. Jurek,
D. Zymierska,
A. Wawro,
A. Petroutchik,
L. Juha, [......],
U. Zastrau,
R. London,
S. Hau-Riege,
C Riekel,
R. Davies, M. Burghammer,
E. Dynowska,
W. Szuszkiewicz,
W. Caliebe,
R. Nietubyc
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ABSTRACT: The article presents preliminary investigation results on the near-surface damage produced by single pulses o fXUV free-electron laser in the amorphous alpha-SiO2, the monocrystalline silicon and the epitaxial films of gold. The irradiation was delivered with single pulses of only 25 fs at a wavelength of 32.5 nm and of energy up to 10 mJ. Structural modifications induced by irradiation were characterized by X-ray
microdiffraction, as well as by the AFM and optical microscopy. Ablation craters of well-defined edges
with smooth interiors and outer embankments surrounding the crater edges were found in the
materials. Polycrystalline phases were revealed in Si and Au film samples, in the embankments and in
central parts of some craters. In alpha-SiO2, a diffraction pattern typical of an amorphous material was
observed without any traces of irradiation-initiated crystallization. A step-like, complete removal of
gold film was evidenced inside craters, with only small gold residues in central part of craters exposed
to higher fluences.
Radiation Physics and Chemistry 01/2009; 78:S46. · 1.23 Impact Factor
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ESRF Spotlight on Science. 10/2008; 68.
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ABSTRACT: Using stroboscopic techniques, diffraction patterns of ballistic paraffin wax microdrops have been observed. The microdrops, generated by a high-temperature ink-jet system, travel through the 1 mum synchrotron radiation beam with a speed of about 1.4 m/s. Diffraction patterns were recorded in flight by a charge couple device with a microchannel plate image intensifier stage, which was activated with the microdrop generation frequency of 1000 Hz during 2 mus. The data show liquid microdrops with a constant temperature up to 8 mm from the ink-jet system capillary exit. The general technique could be adapted for studying fast structural processes, such as protein conformational changes in aqueous microdrops.
The Review of scientific instruments 09/2008; 79(8):086106. · 1.52 Impact Factor
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ABSTRACT: Coherent x-ray diffraction imaging is an x-ray microscopy technique with the potential of reaching spatial resolutions well beyond the diffraction limits of x-ray microscopes based on optics. However, the available coherent dose at modern x-ray sources is limited, setting practical bounds on the spatial resolution of the technique. By focusing the available coherent flux onto the sample, the spatial resolution can be improved for radiation-hard specimens. A small gold particle (size <100 nm) was illuminated with a hard x-ray nanobeam (E=15.25 keV, beam dimensions approximately 100 x 100 nm2) and is reconstructed from its coherent diffraction pattern. A resolution of about 5 nm is achieved in 600 s exposure time.
Physical Review Letters 08/2008; 101(9):090801. · 7.37 Impact Factor
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ABSTRACT: We report a scanning technique, which combines high resolution x-ray diffraction (in reciprocal space) along with a submicrometer spatial resolution (in real space). SiGe/Si(001) Stranski–Krastanow islands served here as a well investigated model system to check the limits of the developed method. A set of refractive silicon x-ray lenses focused the x-ray beam size down to a diameter of 200 nm (full width at half maximum), which enables scanning of individual micrometer-sized and even smaller islands. By illuminating diverse {111} island side facets, crystal truncation rods of different orientations were independently excited and thus became distinguishable in the scattering patterns. The reassembling of these locally resolved diffraction patterns coincides with both an integral measurement and a corresponding scattering simulation.
Applied Physics Letters 05/2008; 92(19):193109-193109-3. · 3.84 Impact Factor
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ABSTRACT: The thermal behavior up to degradation of Bombyx mori silk has been studied by scanning synchrotron radiation microdiffraction, gel electrophoresis, and mechanical testing. The diffraction patterns from single baves can be separated into scattering from anisotropic crystalline beta-sheet domains and random short-range order. In contrast to dragline silk, scattering from oriented, short-range-order fibroin is not observed. The sheath of sericin proteins can be selectively probed by a microbeam and shows also principally random short-range-order domains with a small crystalline beta-sheet fraction. Microdiffraction experiments on single baves from 100 to 573 K show an increase in lattice expansion along the [010] chain-stacking direction above 200-250 K, which could be due to an increase in side-chain mobility. Degradation of the crystalline fraction commences at approximately 500 K, and the fibers have become amorphous at about 570 K with an onset of carbonization. Gel electrophoresis shows that the degradation of FibH molecules starts already at about 350 K, while FibL molecules start degrading at about 400 K. The mechanical properties of single baves such as strain-to-failure and tensile strength also start degrading at about 400 K, while the initial modulus increases up to about 475 K. It is proposed that this is due to the development of cross-linking in the short-range-order chain fraction.
Biomacromolecules 12/2007; 8(11):3548-56. · 5.48 Impact Factor
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ABSTRACT: Archaeological cellulose textile fibres (linen and cotton) from caves in the Dead Sea region were investigated using synchrotron
X-ray microdiffraction. The degradation of the up to 2100year old fibres was found to depend on the climatic conditions at
the place of storage. The size and the lattice parameters of the cellulose nanocrystals (microfibrils) in the fibres change
upon degradation; these parameters are shown to be strongly correlated, leading to a microscopic description of the degradation
process in terms of molecular disorder. Artificial ageing does not seem to reproduce the effects observed here for the first
time on archaeological cellulose fibres.
Applied Physics A 11/2007; 89(4):877-881. · 1.63 Impact Factor
