Beugung im inhomogenen Primärstrahlwellenfeld. I. Prinzip einer Phasenmessung von Elektronenbeungungsinterferenzen

Hoppe, W.

doi:10.1107/s0567739469001045

Cited by 326 publications

(142 citation statements)

References 0 publications

Supporting

Mentioning

142

Contrasting

Order By: Relevance

“…This phase retrieval approach has been successfully used for in-situ [6,7] Recently, x-ray Bragg ptychography methods have been developed that eliminate the requirement for isolated crystals and accommodate a broader range of samples. Originally proposed for electron microscopy [9,10] and developed extensively with x-rays in the transmission geometry [11,12], the present form of ptychography consists of inverting a set of far-field diffraction intensity patterns collected from overlapping regions of the sample illuminated with a localized beam. Thus, specific regions of interest can be imaged in continuous samples.…”

Section: Introductionmentioning

confidence: 99%

High-resolution three-dimensional structural microscopy by single-angle Bragg ptychography

et al. 2016

View full text Add to dashboard Cite

We present an efficient method of imaging 3D nanoscale lattice behavior and strain fields in crystalline materials with a new methodology -three dimensional Bragg projection ptychography (3DBPP). In this method, the 2D sample structure information encoded in a coherent high-angle Bragg peak measured at a fixed angle is combined with the real-space scanning probe positions to reconstruct the 3D sample structure. This work introduces an entirely new means of three dimensional structural imaging of nanoscale materials and eliminates the experimental complexities associated with rotating nanoscale samples. We present the framework for the method and demonstrate our approach with a numerical demonstration, an analytical derivation, and an experimental reconstruction of lattice distortions in a component of a nanoelectronic prototype device.Inversion methods provide a powerful alternative to traditional objective-lens-based microscopy. Techniques that numerically invert coherent diffraction patterns into real space images have provided substantial gains in resolution and sensitivity in certain optical, electron, and x-ray microscopy experiments, especially where image-forming lenses are inefficient or difficult to incorporate. The resulting images, formed by inverting reciprocal space diffraction patterns, contain quantitative information that encodes local physical parameters such as permittivity, density, and atomic displacement at sub-beam-size spatial resolutions.When implemented with hard x-rays, these coherent diffraction imaging (CDI) techniques have enhanced our understanding of the internal structure of nano-and meso-scale materials, especially in operating environments that are difficult to access with other probes. Furthermore, x-ray microscopy methods based on Bragg diffraction are of particular interest because the sensitivity of x-rays to crystalline distortions in materials can be leveraged to reveal the interplay between structure and properties without disturbing environmental boundary conditions. However, the routine application of inversion methods to coherent hard x-ray Bragg diffraction is still limited by stringent experimental requirements and long measurement times.Given the potential impact of non-destructive 3D structural microscopy and the limitations of current 3D Bragg coherent x-ray inversion methods, advances in Bragg phase retrieval methods that facilitate the rapid imaging of crystal lattice behavior in realistic environments are critically important. Here, we introduce a new coherent Bragg diffraction imaging approach, three dimensional Bragg projection ptychography (3DBPP), that provides such a capability. 3DBPP enables 3D image reconstruction from a series of 2D Bragg diffraction patterns measured at a single incident beam angle, thus forming a new mode of inversion-based 3D strain-sensitive imaging. As we discuss in this article, 3DBPP is a hybrid real / reciprocal space technique that takes advantage of the high angle of separation between the incident and diffracted beam in a Bra...

show abstract

Section: Introductionmentioning

confidence: 99%

High-resolution three-dimensional structural microscopy by single-angle Bragg ptychography

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The traditional CDI approach requires that samples meet a so-called "finite support" (17) requirement with no observable scattering outside of a defined region; although some limited success has been obtained (18,19), this finite support condition has proven difficult to achieve with single cells surrounded by ice layers. Ptychography (20)(21)(22)) is a recently realized CDI method [with an older history (23)] that circumvents this isolated cell requirement by instead scanning a limitedsize coherent illumination spot across the sample. Ptychography has been used to image freeze-dried diatoms at 30-nm resolution (24) and bacteria at 20-nm resolution (25), and frozen-hydrated yeast at 85-nm resolution (26), whereas ptychographic tomography has been used to image nanoporous glass to 16-nm 3D resolution (27).…”

mentioning

confidence: 99%

Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae

Deng

Vine

Chen

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

164

131

View full text Add to dashboard Cite

Trace metals play important roles in normal and in disease-causing biological functions. X-ray fluorescence microscopy reveals trace elements with no dependence on binding affinities (unlike with visible light fluorophores) and with improved sensitivity relative to electron probes. However, X-ray fluorescence is not very sensitive for showing the light elements that comprise the majority of cellular material. Here we show that X-ray ptychography can be combined with fluorescence to image both cellular structure and trace element distribution in frozen-hydrated cells at cryogenic temperatures, with high structural and chemical fidelity. Ptychographic reconstruction algorithms deliver phase and absorption contrast images at a resolution beyond that of the illuminating lens or beam size. Using 5.2-keV X-rays, we have obtained sub-30-nm resolution structural images and ∼90-nm-resolution fluorescence images of several elements in frozen-hydrated green algae. This combined approach offers a way to study the role of trace elements in their structural context. ptychography | X-ray fluorescence microscopy | cryogenic biological samples X -ray fluorescence microscopy (XFM) offers unparalleled sensitivity for quantitative mapping of elements, especially trace metals which play a critical role in many biological processes (1-3). It is complementary to light microscopy, which can study some elemental content in live cells (with superresolution techniques possible) but which is more difficult to quantitate because it depends on the binding affinities of fluorophores. However, XFM does not usually show much cellular ultrastructure, because the light elements (such as H, C, N, and O, which are the main constituents of biological materials) have low fluorescence yield (4). At the multi-keV X-ray energies needed to excite most X-ray fluorescence lines of interest, these light elements show little absorption contrast, but phase contrast can be used to image cellular structure (5, 6) and this can be combined with scanned-beam XFM (7-11).One can also acquire phase-contrast X-ray images with a resolution beyond X-ray lens limits by recording the diffraction pattern from a coherently illuminated, noncrystalline sample in an approach called coherent diffraction imaging (CDI) (12). This approach has been used to image isolated dried cells (13-15), and 3-nm resolution has been achieved when imaging silver nanocubes (16). The traditional CDI approach requires that samples meet a so-called "finite support" (17) requirement with no observable scattering outside of a defined region; although some limited success has been obtained (18,19), this finite support condition has proven difficult to achieve with single cells surrounded by ice layers. Ptychography (20-22) is a recently realized CDI method [with an older history (23)] that circumvents this isolated cell requirement by instead scanning a limitedsize coherent illumination spot across the sample. Ptychography has been used to image freeze-dried diatoms at 30-nm resolution (24) and bacter...

show abstract

“…In its original form, it was developed as a solution to the phase problems for thin organic crystal in electron microscopy [20]. In that case, structure factor phases can be obtained if the coherent convergent-beam orders overlap, as shown by Spence [24] and, with experimental soft X-ray patterns, by Chapman [21].…”

Section: Phase Information In Overlapping Coherent Ordersmentioning

confidence: 99%

“…Each incident plane-wave gives rise to an outgoing scattered plane-wave. This arrangement was proposed by Hoppe [20] (as ptychography) for phase determination in electron microscopy, and a related analysis, based on the use of Wigner distributions, has been given by Chapman [21] for experimental soft X-ray diffraction patterns. To understand this arrangement, we set the expression for the radius of the beam diameter, r p ¼ 0.61 l/u c , equal to the period of the lattice b ¼ l/(2u B ), as shown in figure 9.…”

Section: Beam Smaller Than Unit Cellmentioning

confidence: 99%

Coherent convergent-beam time-resolved X-ray diffraction

Spence

Zatsepin

2014

Phil. Trans. R. Soc. B

View full text Add to dashboard Cite

The use of coherent X-ray lasers for structural biology allows the use of nanometre diameter X-ray beams with large beam divergence. Their application to the structure analysis of protein nanocrystals and single particles raises new challenges and opportunities. We discuss the form of these coherent convergent-beam (CCB) hard X-ray diffraction patterns and their potential use for time-resolved crystallography, normally achieved by Laue (polychromatic) diffraction, for which the monochromatic laser radiation of a free-electron X-ray laser is unsuitable. We discuss the possibility of obtaining single-shot, angle-integrated rocking curves from CCB patterns, and the dependence of the resulting patterns on the focused beam coordinate when the beam diameter is larger or smaller than a nanocrystal, or smaller than one unit cell. We show how structure factor phase information is provided at overlapping interfering orders and how a common phase origin between different shots may be obtained. Their use in refinement of the phase-sensitive intensity between overlapping orders is suggested.

show abstract

Beugung im inhomogenen Primärstrahlwellenfeld. I. Prinzip einer Phasenmessung von Elektronenbeungungsinterferenzen

Cited by 326 publications

References 0 publications

High-resolution three-dimensional structural microscopy by single-angle Bragg ptychography

High-resolution three-dimensional structural microscopy by single-angle Bragg ptychography

Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae

Coherent convergent-beam time-resolved X-ray diffraction

Contact Info

Product

Resources

About