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ABSTRACT: Best of both worlds: Electrochemical X-ray photolithography combines the advantages of X-ray photolithography with the versatility of electrochemical processing. A proof-of-concept was carried out by electrochemical deposition of nickel under coherent X-ray illumination guided through a lithographic mask with a 4 micrometer pitch, resulting in formation of a nickel grating.
Angewandte Chemie International Edition 10/2012; · 13.45 Impact Factor
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ABSTRACT: The vertical deposition technique for creating crystalline microstructures is applied for the first time to nonspherical colloids in the form of hollow silica cubes. Controlled deposition of the cubes results in large crystalline films with variable symmetry. The microstructures are characterized in detail with scanning electron microscopy and small-angle X-ray scattering. In single layers of cubes, distorted square to hexagonal ordered arrays are formed. For multilayered crystals, the intralayer ordering is predominantly hexagonal with a hollow site stacking, similar to that of the face centered cubic lattice for spheres. Additionally, a distorted square arrangement in the layers is also found to form under certain conditions. These crystalline films are promising for various applications such as photonic materials.
Langmuir 04/2012; 28(20):7631-8. · 4.19 Impact Factor
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ABSTRACT: This paper describes a tunable X-ray focusing apparatus, referred to as a transfocator, based on compound refractive lenses. By varying the number of lenses in the beam, the X-ray energy focused and the focal length can be varied continuously throughout a large range of energies and distances. The instrument can be used in both white and monochromatic beams to focus, pre-focus or collimate the beam. The transfocator can be used with other monochromators and/or other focusing elements, leading to significant increases in flux. Furthermore, the chromatic nature of the focusing means the transfocator suppresses harmonics and can also be used as an extremely high flux broad-band-pass monochromator. These devices have been installed in the first optics and second experimental hutches at the ID11 beamline at the ESRF.
Journal of Synchrotron Radiation 03/2011; 18(Pt 2):125-33. · 2.73 Impact Factor
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Advanced Materials 08/2010; 22(30):3256-9. · 13.88 Impact Factor
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Jan Hilhorst,
Vera V Abramova,
Alexander Sinitskii,
Nina A Sapoletova,
Kirill S Napolskii,
Andrey A Eliseev,
Dmytro V Byelov,
Natali A Grigoryeva,
Alexandra V Vasilieva,
Wim G Bouwman,
Kristina Kvashnina, Anatoly Snigirev,
Sergey V Grigoriev,
Andrei V Petukhov
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ABSTRACT: Using microradian X-ray diffraction, we investigated the crystal structure of convectively assembled colloidal photonic crystals over macroscopic (0.5 mm) distances. Through adaptation of Wilson's theory for X-ray diffraction, we show that certain types of line defects that are often observed in scanning electron microscopy images of the surface of these crystals are actually planar defects at 70.5 degrees angles with the substrate. The defects consist of two parallel hexagonal close-packed planes in otherwise face-centered cubic crystals. Our measurements indicate that these stacking faults cause at least 10% of stacking disorder, which has to be reduced to fabricate high-quality colloidal photonic crystals.
Langmuir 10/2009; 25(17):10408-12. · 4.19 Impact Factor
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ABSTRACT: This chapter presents a summary of micro-focusing optics and methods for X-rays in the energy range 4–100 keV, as provided
by synchrotron radiation sources. The advent of third generation storage rings such as the ESRF, the APS and Spring-8 with
X-ray beams of high brilliance, low divergence and high coherence has made possible efficient X-ray focusing and imaging.
The main emphasis is on those methods which aim to produce submicrometre and nanometre spatial resolutions in imaging applications.
These methods fall into three broad categories: reflective, refractive and diffractive optics. The basic principles and recent
achievements are discussed for optical devices in each of these categories.
03/2008: pages 255-285;
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ABSTRACT: The development of 3rd generation synchrotron radiation sources like European Synchrotron Radiation Facility (ESRF) in parallel with recent advances in the technology of X-ray microfocusing elements like Kirkpatrick-Baez (KB) mirrors, diffractive (Fresnel zone plates, FZP) and refractive (compound refractive lenses, CRL) optics, makes it possible to use X-ray microscopy techniques with high energy X-rays (energy superior to 4 keV). Spectroscopy, imaging, tomography and diffraction studies of samples with hard X-rays at micrometre and sub-micrometre spatial resolutions are now possible. The concept of combining these techniques as a high-energy microscopy has been proposed and successfully realized at the ESRF beamlines. Therefore a short summary of X-ray microscopy techniques is presented first. The main emphasis will be put on those methods which aim to produce sub-micron and nanometre resolution. These methods fall into three broad categories: reflective, refractive and diffractive optics. The basic principles and recent achievements will be discussed for all optical devices. Recent applications of synchrotron based microanalytical techniques to characterise radioactive fuel particles (UO(2)) released from the Chernobyl reactor are reported.
Journal of Environmental Monitoring 02/2006; 8(1):33-42. · 1.99 Impact Factor
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ABSTRACT: The combination of X-ray microdiffraction and microfluidics is used to investigate the dynamic behaviour of soft materials. A microfocused X-ray beam enables the observation of the influence of droplet formation on the nanostructure of a smectic liquid crystal in water. Using a hydrodynamic focusing device, the evolution of the intercalation of DNA into multilamellar membranes can be studied. Owing to the elongational flow at the centre of this device, alignment of the material is induced which allows for an improved structural characterization. Furthermore, the influence of strain applied to these materials can be tested.
Journal of Synchrotron Radiation 12/2005; 12(Pt 6):745-50. · 2.73 Impact Factor
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ABSTRACT: We introduce a microprobe technique based on the x-ray standing wave method (XSW) demonstrating that structural analysis can be achieved with chemical sensitivity on a microscopic scale. We apply this XSW microscopy technique to study an epitaxially grown GaAs/Al <sub>0.1</sub> Ga <sub>0.9</sub> As/GaAs (001) heterostructure in cross section. We focus the x-ray beam by a refractive lens onto the cleaved sample and analyze the constituent elements within the 4 μm thick Al <sub>0.1</sub> Ga <sub>0.9</sub> As layer resolving the substitutional location of Al. The new micro-XSW technique will permit microscopic examinations of the structure of integrated semiconductor devices or microscopic crystalline grains with chemical sensitivity and structural resolution on the pm scale. © 2002 American Institute of Physics.
Applied Physics Letters 10/2002; · 3.84 Impact Factor
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ABSTRACT: The present status of X-ray optics in high-energy domain, an area in which much progress has been made in recent years, is reviewed with respect to lateral resolution, flux, imaging capability. The latest results on development of new focusing devices such as compound refractive lenses are shown. Hard X-ray microscopy techniques realized at the ESRF undulator beamline ID22 are presented. Some recent application in imaging, spectroscopy and microdiffraction are briefly described. © 2000 American Institute of Physics.
AIP Conference Proceedings. 05/2000; 507(1):76-83.
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ABSTRACT: Refractive x-ray lenses have recently been applied for imaging and scanning microscopy with hard x rays. We report the application of refractive lenses in an optical scheme for high-resolution x-ray diffraction, performed at a high brilliance synchrotron radiation source. An experimental proof of principle and a theoretical discussion are presented. In particular, we observe the x-ray diffraction pattern from a two-dimensional photonic crystal with 4.2 µm periodicity, which normally is employed to scatter light in the infrared.
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ABSTRACT: Microradian X-ray diffraction from sedimentary colloidal crystals is studied using synchrotron radiation with photon energies of 12.4, 27, and 38 keV. Stacking disorder in these hard-sphere crystals leads to diffuse X-ray scattering along the Bragg scattering rods normal to the randomly stacked layers. We observed the appearance of diffuse scattering, shown to be induced by multiple scattering, along the secondary Bragg rods in between the stacking-independent true Bragg reflections. This effect can be reduced by measuring at higher X-ray energies.
