Diffractive X-ray Research Articles

Dynamic X-ray Coherent Diffraction Analysis: Bridging the Time Scales between Imaging and Photon Correlation Spectroscopy.

The advent of diffraction limited sources and developments in detector technology opens up new possibilities for the study of materials in situ and operando. Coherent X-ray diffraction techniques such as coherent X-ray diffractive imaging (CXDI) and X-ray photon correlation spectroscopy (XPCS) are capable for this purpose and provide complementary information, although due to signal-to-noise requirements, their simultaneous demonstration has been limited. Here, we demonstrate a strategy for the simultaneous use of CXDI and XPCS to study in situ the Brownian motion of colloidal gold nanoparticles of 200 nm diameter suspended in a glycerol-water mixture. We visualize the process of agglomeration, examine the spatiotemporal space accessible with the combination of techniques, and demonstrate CXDI with 22 ms temporal resolution.

Rapid aberration correction for diffractive X-ray optics by additive manufacturing: erratum

An erratum is presented to correct the stated numerical aperture of the employed multilayer Laue lenses in our previously published paper [Opt. Express 30, 31519 (2022)10.1364/OE.454863].

In situ coherent x-ray scattering reveals polycrystalline structure and discrete annealing events in strongly coupled nanocrystal superlattices

Solution-phase bottom up self-assembly of nanocrystals into superstructures such as ordered superlattices is an attractive strategy to generate functional materials of increasing complexity, including very recent advances that incorporate strong interparticle electronic coupling. While the self-assembly kinetics in these systems have been elucidated and related to the product characteristics, the weak interparticle bonding interactions suggest the superstructures formed could continue to order within the solution long after the primary nucleation and growth have occurred, even though the mechanism of annealing remains to be elucidated. Here, we use a combination of Bragg coherent diffractive imaging and x-ray photon correlation spectroscopy to create real-space maps of supercrystalline order along with a real-time view of the strain fluctuations in aging strongly coupled nanocrystal superlattices while they remain suspended and immobilized in solution. By combining the results, we deduce that the self-assembled superstructures are polycrystalline, initially comprising multiple nucleation sites, and that shear avalanches at grain boundaries continue to increase crystallinity long after growth has substantially slowed. This multimodal approach should be generalizable to characterize a breadth of materials in their native chemical environments, thus extending the reach of high-resolution coherent x-ray characterization to the benefit of a much wider range of physical systems. Published by the American Physical Society 2024

Numerical simulations of temperature loads on multilayer Laue lenses

We present numerical simulations of the heat loads on novel diffractive X-ray optics, known as multilayer Laue lenses, exposed to high-intensity X-ray beams produced by an X-ray free electron laser (XFEL). These lenses can be used to focus XFEL beams to nanometer spots. The temperature distribution within the lens and temperature evolution as a function of incident pulse frequencies were calculated for two different lens geometries and several material pairs and material ratios of the MLLs. Simulations considered the special pulse structure of European XFEL with X-rays being delivered in pulse trains. After defining the geometric model, computational grid, material properties, and boundary conditions, a grid sensitivity study was carried out. We solved the transient heat energy transport equation in solids for mixed boundary conditions. The results of these simulations will help select materials and lens geometry for future XFEL experiments.

Coherent diffractive imaging with twisted X-rays: Principles, applications, and outlook

Recent technological breakthroughs in synchrotron and x-ray free electron laser facilities have revolutionized nanoscale structural and dynamic analyses in condensed matter systems. This review provides a comprehensive overview of the advancements in coherent scattering and diffractive imaging techniques, which are now at the forefront of exploring materials science complexities. These techniques, notably Bragg coherent diffractive imaging and x-ray photon correlation spectroscopy, x-ray magnetic dichroism, and x-ray correlation analysis leverage beam coherence to achieve volumetric three-dimensional imaging at unprecedented sub-nanometer resolutions and explore dynamic phenomena within sub-millisecond timeframes. Such capabilities are critical in understanding and developing advanced materials and technologies. Simultaneously, the emergence of chiral crystals—characterized by their unique absence of standard inversion, mirror, or other roto-inversion symmetries—presents both challenges and opportunities. These materials exhibit distinctive interactions with light, leading to phenomena such as molecular optical activity, chiral photonic waveguides, and valley-specific light emissions, which are pivotal in the burgeoning fields of photonic and spintronic devices. This review elucidates how novel x-ray probes can be leveraged to unravel these properties and their implications for future technological applications. A significant focus of this review is the exploration of new avenues in research, particularly the shift from conventional methods to more innovative approaches in studying these chiral materials. Inspired by structured optical beams, the potential of coherent scattering techniques utilizing twisted x-ray beams is examined. This promising direction not only offers higher spatial resolution but also opens the door to previously unattainable insights in materials science. By contextualizing these advancements within the broader scientific landscape and highlighting their practical applications, this review aims to chart a course for future research in this rapidly evolving field.

Effect of MPA capping on the structural, optical and thermal properties of Zn0.96Ni0.04S nanoparticles

Chemical precipitation method was used to prepare of Zn0.96Ni0.04S nanoparticles. XRD showed that ZnS:Ni2+ nanoparticles crystallized in zinc blend structure with preferential orientation by the side of (111) plane. Scanning electron microscope (SEM) images of Zn0.96Ni0.04S nanoparticles portray substantial agglomeration of particles with potholed spherical morphology and energy dispersive spectrum (EDAX) measurements incorrigible that the presence of Ni in ZnS lattice. High resolution tunneling electron microscope (HRTEM) divulge that Zn0.96Ni0.04S particle size were ranges from ∼ 15 to 20 nm with good crystalline character and SAED pattern were good concurrence with X-ray diffractive (XRD) results. UV–Vis spectroscopy was engage to evaluate optical band gap of Zn0.96Ni0.04S nanoparticle, and which further disclose that when 3-mercaptopropionic (MPA) concentration increase guide the absorption edge shifted to lower wavelength. Peak at 411 °C with matching weight loss of 39.2 wt% in DTA reveals that Ni2+ ions are get away from the ZnS matrix.

Effects of Extracts of Alchornea Cordifolia on Biocorrosion Control on Sewer Concrete

Concrete infrastructures that make up the sewer system exposed to sewer waste waters are often subjected to microbial corrosion. The biogenic sulfuric acid produced by the activity of sulfur-oxidizing bacteria A.thiooxidans attacks concrete in sewers leading to loss of concrete mass and deterioration.The aim of this study was to control concrete biodegradation using plant extracts of Alchornea Cordifolia. Concrete samples were corroded for 26 months in real sewer wastewater conditions. The influence of biogenic sulfuric acid on the biocorrosion of concrete samples was determined in terms of weight loss, pH, sulfate concentration variation, chemical composition changes, and formation of corrosion by-products. Recorded corrosion rates before coating were between 0.071996mpy –1.168546mpy. Changes in sample morphology, ettringite and gypsum formed were observed by X-ray diffraction and SEM methods with corrosion progression.Phytochemicals analysis of extracts samples confirmed the presence of tannins, saponins, flavonoids, and terpenoids produced in plant tissues. GC-MS analysis of the ethanolic extracts identified 26 compounds.The most dominant being Eugenol.Biocorrosion control determined the effects of extracts on concrete corrosion in sewer waters. A marked decline in the rates of corrosion with each extract's coating was recorded for extracts coated concretes (0.002589mpy-0.003256mpy). An increase in inhibition efficiency with an increase in extract concentration was observed and was in the range of50% A.Cordifolia extracts gave the highest inhibitor efficiency. X-ray diffractive analysis and scanning electron microscopy showed morphological variations in concrete before and after coating. Results of ANOVA showed inhibitor concentration as having the most significant effect on the extracts' corrosion inhibition

PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE FROM AQUEOUS SOLUTION USING BASE MODIFIED TERMITE SOIL UNDER UV LIGHT IRRADIATION

Photocatalysis is an effective treatment method for removal of toxic pollutants from industrial wastewaters. Sodium hydroxide was used to modified termite mound soil obtained from Ahmadu Bello University Zaria, Kaduna State, Nigeria. The soil was washed with deionized water and placed in an oven set at 60oC for 6 hrs before crushing with an aggregate impact crusher, sieved with 0.075 m mesh pore size. The sieved soil sample was tagged as unmodified-TMS (termite mound soil). The soil sample was modified using sodium hydroxide (NaOH) at different concentrations (5 %, 10 %, 15 %, and 20 % W/V). The modified and unmodified-TMS catalysts were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray fluorescence (XRF), Electron diffractive X-ray (EDX), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), thermogravimetric analyses (TGA), and Selected area electron diffraction (SAED), The photocatalytic activity of the unmodified-TMS, 5 % NaOH, 10 % TMS-NaOH, 15 % TMS-NaOH, and 20 % TMS-NaOH, were assessed by testing the degradation rate of Methylene Blue under ultraviolet light irradiation. The results indicated that the samples exhibited the best photocatalytic activity at optimum parameters of catalyst dosage 2.5 g /L. pH 9 and 125 mg/L concentration of MB this is evidenced by the highest methylene degradation rate of (74 %). The photocatalytic degradation of the Methylene blue dye was found to obey first-order kinetics.

MODIFICATION OF TERMITE MOUND SOIL USING PHOSPHORIC ACID FOR PHOTODEGRADATION OF METHYLENE BLUE DYE UNDER UV LIGHT IRRADIATION

Termite mound was mined from the termite nest spotted at Ahmadu Bello University, Zaria Kaduna State, Nigeria. It was washed with deionized water and placed in an oven set at 60oC for 6 hrs before crushing with an aggregate impact crusher and sieved into 0.075 m mesh pore size. The sieved soil sample was tagged as unmodified-TMS (termite mound soil). The soil sample was modified using orthophosphoric acid (H3PO4) at different (5 %, 10 %, 15 %, and 20 %) concentrations. The modified and unmodified-TMS were characterized by the methods of scanning electronic microscope (SEM), transmission electron microscope (TEM), Electron diffractive X-ray (EDX), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), thermogravimetric analyses (TGA), and Selected area electron diffraction (SAED), The photocatalytic activity of the unmodified-TMS, 5 % TMS-H3PO4, 10 % TMS-H3PO4 , 15 % TMS-H3PO4 , and 20 % TMS-H3PO4, were assessed by testing the degradation rate of Methylene Blue under ultraviolet light irradiation using optimum parameters (1.5 g/L, pH 11 & 75 mg/L). The results indicated that the samples exhibited the best photocatalytic activity at optimum parameters of catalyst dosage 1.5 g /L. pH 11 and 75 mg/L concentration of MB as evidenced by the highest methylene degradation rate of (88 %). The photocatalytic degradation of Methylene blue dye was found to obey first-order kinetics.

Rapid aberration correction for diffractive X-ray optics by additive manufacturing.

Diffraction-limited hard X-ray optics are key components for high-resolution microscopy, in particular for upcoming synchrotron radiation sources with ultra-low emittance. Diffractive optics like multilayer Laue lenses (MLL) have the potential to reach unprecedented numerical apertures (NA) when used in a crossed geometry of two one-dimensionally focusing lenses. However, minuscule fluctuations in the manufacturing process and technical limitations for high NA X-ray lenses can prevent a diffraction-limited performance. We present a method to overcome these challenges with a tailor-made refractive phase plate. With at-wavelength metrology and a rapid prototyping approach we demonstrate aberration correction for a crossed pair of MLL, improving the Strehl ratio from 0.41(2) to 0.81(4) at a numerical aperture of 3.3 × 10-3. This highly adaptable aberration-correction scheme provides an important tool for diffraction-limited hard X-ray focusing.

Non-destructive 3D orientational mapping of bone using diffractive X-ray tomography

Non-destructive 3D orientational mapping of bone using diffractive X-ray tomography

An Analytic Method of Phase Retrieval for X-Ray Phase Contrast Imaging

New lensless diffractive X-ray technic for micro-scale imaging of biological tissue is based on quantitative information on the phase. This method yields improved contrast compared to purely absorption-based tomography but involves a phase retrieval problem since of physical limitation of detectors. An analytic method is proposed in the paper for reconstruction of the ray projection of complex refraction index from intensity distribution of one hologram.

Comparison of distributed memory algorithms for X-ray wave propagation in inhomogeneous media.

Calculations of X-ray wave propagation in large objects are needed for modeling diffractive X-ray optics and for optimization-based approaches to image reconstruction for objects that extend beyond the depth of focus. We describe three methods for calculating wave propagation with large arrays on parallel computing systems with distributed memory: (1) a full-array Fresnel multislice approach, (2) a tiling-based short-distance Fresnel multislice approach, and (3) a finite difference approach. We find that the first approach suffers from internode communication delays when the transverse array size becomes large, while the second and third approaches have similar scaling to large array size problems (with the second approach offering about three times the compute speed).

Multifocus off-axis zone plates for x-ray free-electron laser experiments

X-ray free-electron lasers (XFELs) are paving the way towards new experiments in many scientific fields, such as ultrafast science, nonlinear spectroscopy, and coherent imaging. However, the strong intensity fluctuations inherent to the lasing process in these sources often lead to problems in signal normalization. In order to address this challenge, we designed, fabricated, and characterized diffractive x-ray optics that combine the focusing properties of a Fresnel zone plate with the beam-splitting capability of a grating in a single diffractive optical element. The possibility to split the incident beam into identical copies allows for direct shot-to-shot normalization of the sample signal, thereby greatly enhancing the signal-to-noise ratio in experiments with XFEL radiation. Here we propose two schemes for the design of such diffractive x-ray optical elements for splitting and focusing an incoming beam into up to three foci by merging a grating with a focusing zone plate. By varying the duty cycle of the grating or the relative shift of the Fresnel zone plate structure, we are able to tune the relative intensities of the different diffraction orders to achieve the desired splitting ratios. Experimental confirmation of the design is provided with soft x-ray light (540 eV) and shows a good agreement with calculations, confirming the suitability of this approach for XFEL experiments.

Alumina-based Coating for Coke Reduction in Steam Crackers.

Alumina-based coatings have been claimed as being an advantageous modification in industrial ethylene furnaces. In this work, on-line experimentally measured coking rates of a commercial coating (CoatAlloy™) have pointed out its superiority compared to an uncoated reference material in an electrobalance set-up. Additionally, the effects of presulfiding with 500 ppmw DMDS per H2O, continuous addition of 41 ppmw S per HC of DMDS, and a combination thereof were evaluated during ethane steam cracking under industrially relevant conditions (Tgasphase = 1173 K, Ptot = 0.1 MPa, XC2H6 = 70%, dilution δ = 0.33 kgH2O/kgHC). The examined samples were further evaluated using online thermogravimetry, scanning electron microscopy and energy diffractive X-ray for surface and cross-section analysis together with X-ray photoelectron spectroscopy and wavelength-dispersive X-ray spectroscopy for surface analysis. The passivating coating illustrated a better performance than the reference Ni-Cr Fe-base alloy after application of an improved pretreatment, followed by piddling changes on the product distribution. Presulfiding of the coating affected negatively the observed coking rates in comparison with the reference alloy, so alternative presulfiding and sulfur addition strategies are recommended when using this barrier coating.

Imaging shape and strain in nanoscale engineered semiconductors for photonics by coherent x-ray diffraction

Coherent x-ray diffractive imaging is a nondestructive technique that extracts three-dimensional electron density and strain maps from materials with nanometer resolution. It has been utilized for materials in a range of applications, and has significant potential for imaging buried nanostructures in functional devices. Here, we show that coherent x-ray diffractive imaging is able to bring new understanding to a lithography-based nanofabrication process for engineering the optical properties of semiconducting GaAs1-yNy on a GaAs substrate. This technique allows us to test the process reliability and the manufactured patterns quality. We demonstrate that regular and sharp geometrical structures can be produced on a few-micron scale, and that the strain distribution is uniform even for highly strained sub-microscopic objects. This nondestructive study would not be possible using conventional microscopy techniques. Our results pave the way for tailoring the optical properties of emitters with nanometric precision for nanophotonics and quantum technology applications.

Mode-Resolved Detection of Magnetization Dynamics Using X-ray Diffractive Ferromagnetic Resonance.

Collective spin excitations of ordered magnetic structures offer great potential for the development of novel spintronic devices. The present approach relies on micromagnetic models to explain the origins of dynamic modes observed by ferromagnetic resonance (FMR) studies, since experimental tools to directly reveal the origins of the complex dynamic behavior are lacking. Here we demonstrate a new approach which combines resonant magnetic X-ray diffraction with FMR, thereby allowing for a reconstruction of the real-space spin dynamics of the system. This new diffractive FMR technique builds on X-ray detected FMR that allows for element-selective dynamic studies, giving unique access to specific wave components of static and dynamic coupling in magnetic heterostructures. In combination with diffraction, FMR is elevated to the level of a modal spectroscopy technique, potentially opening new pathways for the development of spintronic devices.

Diffractive small angle X-ray scattering imaging for anisotropic structures

Insights into the micro- and nano-architecture of materials is crucial for understanding and predicting their macroscopic behaviour. In particular, for emerging applications such as meta-materials, the micrometer scale becomes highly relevant. The micro-architecture of such materials can be tailored to exhibit specific mechanical, optical or electromagnetic behaviours. Consequently, quality control at micrometer scale must be guaranteed over extended areas. Mesoscale investigations over millimetre sized areas can be performed by scanning small angle X-ray scattering methods (SAXS). However, due to their long measurement times, real time or operando investigations are hindered. Here we present a method based on X-ray diffractive optics that enables the acquisition of SAXS signals in a single shot (few milliseconds) over extended areas. This method is applicable to a wide range of X-ray sources with varying levels of spatial coherence and monochromaticity, as demonstrated from the experimental results. This enables a scalable solution of spatially resolved SAXS.

Post-depositional controls on siliciclastic tight reservoirs: Implications from the Oligocene Nyalau Formation (Cycle 1), onshore Central Sarawak, Borneo

Abstract Subsurface tight reservoir sandstones of the Oligocene Nyalau Formation (Cycle I), NW Borneo were studied to understand the variability of its reservoir quality with depth, determine major controls responsible for porosity loss, identify reservoir facies and reconstruct paragenetic sequence. Core samples representing an estimated 125 Feet (38.1 m) interval from an onshore well in Central Sarawak were subjected to thin section, Helium porosimetry, inductively coupled plasma mass spectrometry, x-ray powder diffractometry, scanning electron microscopy and energy diffractive x-ray spectroscopy. The sandstones are fine-to-medium grained and comprise of sublithearenite and subarkose primarily sourced from recycled orogenic sources. Four lithofacies base on textural composition and diagenetic events were identified: (A) matrix dominated sandstone, (B) matrix-free sandstone, (C) quartz-cemented sandstone and (D) clay-coated sandstone. Obtained helium porosity, 0.90–11.52% (Average 4.27%) and Klinkenberg permeability,

Ultimate limitations in the performance of kinoform lenses for hard x-ray focusing

Diffractive x-ray lenses suffer from limited focusing efficiency, which can be improved by replacing the binary nanostructures of the lenses with kinoforms. Here we present the first example of kinoform lenses for x rays and compare their efficiency with those of binary Fresnel zone plates (FZPs), realized through gray-scale-focused Xe ion beam lithography. Unexpectedly, experimental results indicate lower focusing efficiencies of kinoform lenses compared to binary FZPs between 5–7 keV. Simulations that include absorption reveal that kinoform lenses can only provide a limited boost in the diffraction efficiency in multi-keV x-ray energies and for impractical lens thicknesses. Combined with significant challenges in kinoform lens fabrication, the modest gains of this approach may suggest that it is not the path to increasing focusing efficiency.