37 research outputs found
High-resolution strain-mapping during in-situ nanoindentation of CVD thin films
The NanoMAX beamline is a hard X-ray nanoprobe beamline at MAX IV Laboratory, Lund, Sweden. This beamline was designed to take full advantage of the exceptionally low emittance and the resulting coherence properties of the X-ray beam. A nano-focus beam of 50Ă50 nm2 of high X-ray photon intensity is available for experiments. This small focus is ideal to investigate heterogeneous samples in materials science with high spatial resolution, utilizing techniques such as scanning X-ray diffraction, 2D X-ray fluorescence mapping, and coherent imaging in the Bragg geometry.
Chalmers University of Technology and MAX IV Laboratory have acquired a nanoindenter to be installed at the NanoMAX beamline. The combination of in-situ micro-mechanical testing and nano-focused scanning X-ray diffraction permits time-resolved high-resolution in-situ strain mapping. The experimental configuration is based on an Alemnis nanoindenter which is transferrable between the beamline and a scanning electron microscope (SEM). This allows for a sample characterization in a SEM prior to the X-ray beamline experiment. A potential science case is the investigation of local residual stress fields and their changes under increasing load.
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Grain rotation and lattice deformation during photoinduced chemical reactions revealed by in-situ X-ray nanodiffraction
In-situ X-ray diffraction (XRD) and transmission electron microscopy (TEM)
have been used to investigate many physical science phenomena, ranging from
phase transitions, chemical reaction and crystal growth to grain boundary
dynamics. A major limitation of in-situ XRD and TEM is a compromise that has to
be made between spatial and temporal resolution. Here, we report the
development of in-situ X-ray nanodiffraction to measure atomic-resolution
diffraction patterns from single grains with up to 5 millisecond temporal
resolution, and make the first real-time observation of grain rotation and
lattice deformation during photoinduced chemical reactions. The grain rotation
and lattice deformation associated with the chemical reactions are quantified
to be as fast as 3.25 rad./sec. and as large as 0.5 Angstroms, respectively.
The ability to measure atomic-resolution diffraction patterns from individual
grains with several millisecond temporal resolution is expected to find broad
applications in materials science, physics, chemistry, and nanoscience.Comment: 17 pages, 3 figure
X-ray in-line holography and holotomography at the NanoMAX beamline
Coherent X-ray imaging techniques, such as in-line holography, exploit the high brilliance provided by diffraction-limited storage rings to perform imaging sensitive to the electron density through contrast due to the phase shift, rather than conventional attenuation contrast. Thus, coherent X-ray imaging techniques enable high-sensitivity and low-dose imaging, especially for low-atomic-number (Z) chemical elements and materials with similar attenuation contrast. Here, the first implementation of in-line holography at the NanoMAX beamline is presented, which benefits from the exceptional focusing capabilities and the high brilliance provided by MAX IV, the first operational diffraction-limited storage ring up to approximately 300 eV. It is demonstrated that in-line holography at NanoMAX can provide 2D diffraction-limited images, where the achievable resolution is only limited by the 70 nm focal spot at 13 keV X-ray energy. Also, the 3D capabilities of this instrument are demonstrated by performing holotomography on a chalk sample at a mesoscale resolution of around 155 nm. It is foreseen that in-line holography will broaden the spectra of capabilities of MAX IV by providing fast 2D and 3D electron density images from mesoscale down to nanoscale resolution
Real-time Accelerator Diagnostic Tools for the MAX IV Storage Rings
In this paper, beam diagnostic and monitoring tools developed by the MAX IV
Operations Group are discussed. In particular, new beam position monitoring and
accelerator tunes visualization software tools, as well as tools that directly
influence the beam quality and stability are introduced. An availability and
downtime monitoring application is also presented
Ein dediziertes Instrument fĂŒr Röntgenbildgebung mit Wellenleitern
Röntgenmikroskopie ist in den vergangenen
Jahren zu einer leistungsfÀhigen und vielseitigen bildgebenden
Methode in vielen Bereiche der Wissenschaft geworden, mit der opake
Medien bei hoher rÀumlicher Auflösung untersucht werden können. Es
bleibt jedoch eine Herausforderung, geeignete Röntgenlinsen
herzustellen, wie z.B. Frsenlesche Zonenplatten oder refraktive
Linsen. In einem alternativen Ansatz linsenloser Abbildung wird die
Probe mit kohÀrenter Röntgenstrahlung beleuchtet. Die
Probeninformation wird dann aus dem aufgenommenen Streubild durch
numerische, iterative Algorithmen rekonstruiert. In dieser Arbeit
wird zunÀchst die Grundlage von linsenloser holographischer
Abbildung mit Röntgenwellenleitern erlÀutert und zu einem Konzept
der Röntgeninterferometrie mit Wellenleitern erweitert. Die
spezifische Instrumentierung, die erforderlich war fĂŒr
Demonstrationsexperimente mit Röntgenwellenleitern zur
holographischen Abbildung, wird erklÀrt und die erzielten
Ergebnisse prÀsentiert. Basierend auf diesen Ergebnissen der
Demonstrationsexperimente wurde ein Instrument zur holographischen
Abbildung mit Röntgenwellenleitern entwickelt und aufgebaut. Die
Spezifikationen und Eigenschaften des Kirckpatrick-Beaz
Spiegelsystems und anderen mechanischen und optischen Komponenten
werden beschrieben und experimentell charakterisiert, zusammen mit
dem Steuerungssystem und verschiedenen verfĂŒgbaren Detektoren.
Erste Ergebnisse belegen die hohe AbbildungsqualitÀt des
vorgestellten Instruments
A dedicated endstation for waveguide-based x-ray imaging
Softcover, 17x24X-ray microscopy has emerged as a powerful and versatile imaging technique in many fields of science over the last years, offering insights in opaque media at high spatial resolution. A major challenge remains the fabrication of suitable X-ray lenses, e.g., Fresnel zone plates or compound refractive lenses. In an alternative approach of a lensless imaging scheme the sample is illuminated by a coherent X-ray beam. The sample information is then reconstructed from the recorded diffraction signal by numerical iterative algorithms. Within this thesis the basics of lensless holographic imaging with X-Ray waveguides are summarised and extended to the concept of waveguide-based X-ray interferometry. The specific instrumentation required for the conceptual experiments of waveguide-based holographic imaging is explained and illustrated by the obtained results. Based on the results of these conceptual experiments a dedicated synchrotron endstation for waveguide-based holographic imaging was designed and built. The specifications and properties of the Kirkpatrick-Baez focussing mirrors and other mechanical and optical components are described in detail, along with the instrument control system and various available detectors. First commissioning results prove the imaging abilities of the presented endstation
Complete alignment of a KB-mirror system guided by ptychography
We demonstrate how the individual mirrors of a high-quality Kirkpatrick-Baez (KB) mirror system can be aligned to each other to create an optimally focused beam, through minimizing aberrations in the phase of the ptychographically reconstructed pupil function. Different sources of misalignment and the distinctive phase artifacts they create are presented via experimental results from the alignment of the KB mirrors at the NanoMAX diffraction endstation. The catalog of aberration artifacts can be used to easily identify which parameter requires further tuning in the alignment of any KB mirror system
Structure of cellulose in birch phloem fibres in tension wood : an X-ray nanodiffraction study
Peer reviewe
Decomposition pathways in nano-lamellar CVD Ti0.2Al0.8N
Recent progress in chemical vapour deposition (CVD) technology has enabled synthesis of metastable cubic Ti1âxAlxN coatings with x as high as 0.8â0.9. These coatings have unique micro- and nano-structures consisting of grains with epitaxially grown nanolamellae with different Al/Ti ratios, and exhibit exceptional hardness and resistance to wear and oxidation. Here, the thermal stability and decomposition of nano-lamellar CVD Ti0.2Al0.8N at temperatures between 800 and 1000 \ub0C have been investigated using a combination of cross-sectional transmission X-ray nano-diffraction and scanning transmission electron microscopy. The decomposition started by formation of hexagonal AlN (h-AlN) in the grain boundaries throughout the coating. Below 900 \ub0C, only limited further decomposition of the grain interiors occurred. At higher temperatures the formation of grain boundary h-AlN was followed by a bulk transformation of the nano-lamellar structure, starting at the top of the coating and subsequently sweeping inwards. The bulk transformation occurred initially through spinodal decomposition, followed by transformation of the Al-rich cubic phase to h-AlN, leading to a coarsened structure with Ti-rich domains in a h-AlN matrix. The behaviour is explained by the higher capability of grain boundaries and free surfaces to accommodate the volumetric expansion from the h-AlN formation. The results increase our understanding of the complicated decomposition processes in these metastable cubic coatings, which are of utmost importance from both technological and scientific perspectives