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Multilayer Laue lenses (MLLs) have demonstrated great capabilities for efficiently focusing hard X-rays down to the nanometer scale. Optimized use of MLLs in a scanning X-ray microscope requires careful consideration of a number of practical parameters other than resolution and efficiency in order to optimize the microscope's performance and scientific throughput. Here, relationships among the apodization effect owing to the presence of a beamstop, the monochromaticity requirement and the allowable working distance are discussed, as well as their impacts on the performance of the optics. Based on these discussions, optimal MLL schemes aiming at 10 nm resolution for a scanning X-ray microscope for the Hard X-ray Nanoprobe (HXN) beamline at National Synchrotron Light Source II are presented. [ABSTRACT FROM AUTHOR]

We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens. [ABSTRACT FROM AUTHOR]

The authors report a study of structural and chemical disorders in a ternary combinatorial epitaxial film of CoxMnyGe1-x-y in the composition range that includes the Heusler alloy Co2MnGe, using microbeam anomalous x-ray diffraction techniques. The structural and chemical ordering of the alloy has been found to be extremely stable over a large composition range, while elemental site swapping and sublattice vacancies have been identified. A model of anomalous diffraction around the Co and Ge edges is presented and shown to make possible the identification and quantification of these disorders in an epitaxial film. [ABSTRACT FROM AUTHOR]

We used x-ray nanotomography to characterize the three-dimensional (3D) morphology and topology of dealloyed nanoporous gold after coarsening. The interface shape distribution obtained from the nanotomography measurement shows that the coarsening does not proceed by bulk diffusion. The surface normal distribution shows that the morphology of the nanoporous gold is anisotropic. The topology of nanoporous gold is similar to that of other bicontinuous structures created by phase separation, despite the radically different method used to produce the structures. This work opens the door to time-resolved, in situ studies of coarsening of nanoporous gold in 3D. [ABSTRACT FROM AUTHOR]

We report on a developed micromachined silicon platform for the precise assembly of 2D multilayer Laue lenses (MLLs) for high-resolution X-ray microscopy. The platform is 10 × 10 mm2 and is fabricated on ~500 µm thick silicon wafers through multiple steps of photolithography and deep reactive-ion etching. The platform accommodates two linear MLLs in a pre-defined configuration with precise angular and lateral position control. In this work, we discuss the design and microfabrication of the platform, and characterization regarding MLLs assembly, position control, repeatability, and stability. The results demonstrate that a micromachined platform can be used for the assembly of a variety of MLLs with different dimensions and optical parameters. The angular misalignment of 2D MLLs is well controlled in the range of the designed accuracy, down to a few millidegrees. The separation distance between MLLs is adjustable from hundreds to more than one thousand micrometers. The use of the developed platform greatly simplifies the alignment procedure of the MLL optics and reduces the complexity of the X-ray microscope. It is a significant step forward for the development of monolithic 2D MLL nanofocusing optics for high-resolution X-ray microscopy. [ABSTRACT FROM AUTHOR]

The synthesis and magnetic properties of (In1-xFex)2O3-σ bulk ceramics with Cu co-doping are reported. Magnetic Fe ions are found to have high thermodynamic solubility (up to 20%) in the In2O3 host compound. The lattice constant decreases almost linearly as Fe doping concentration increases indicating the incorporation of Fe ions into the host lattice. The samples with high Fe concentration annealed under Ar reduced atmosphere were found to be ferromagnetic, and the Curie temperature is around 750 K. The extensive structural and magnetic studies rule out the possibility that the observed magnetism is derived from magnetic impurity phases. [ABSTRACT FROM AUTHOR]

Human activities result in the emission of 2000 metric tons of mercury compounds annually. Mercury (Hg) biomagnification has been characterized in marine mammals and predatory fish; however, little is known about mercury accumulation in brains of wild terrestrial species. Elevated Hg content, of 1.27 μg/g wet wt.—found in the brain of wild small Indian mongoose, prompted us to use synchrotron X-ray fluorescence imaging for simultaneous, quantitative mapping of biologically relevant and neurotoxic elements with high spatial resolution. X-ray fluorescence combined with immunohistochemistry revealed ~0.5–1.9 micron Hg-rich aggregates in cells of the choroid plexus and astrocytes of the subventricular wall in the mongoose brain. Hg content within aggregates correlated with selenium. Hg aggregates did not co-localize with lysosomes. The low Hg density inside aggregates indicated diffuse Hg binding to a Se-containing biomolecule, rather than much denser HgSe nanoparticles proposed to form in other species. Our data show the susceptibility of the small Indian mongoose population to Hg pollution and highlight the vulnerability of the brain as an organ targeted by mercury. Data also provide evidence on the adaptation in the form of a Se-based detoxification mechanism sequestering Hg into intracellular aggregates. [ABSTRACT FROM AUTHOR]

X-ray fluorescence mapping (XRF) is a highly efficient and non-invasive technique for quantifying material composition with micro and nanoscale spatial resolutions. Quantitative XRF analysis, however, confronts challenges from the long-lasting problem called self-absorption. Moreover, correcting two-dimensional XRF mapping datasets is particularly difficult because it is an ill-posed inverse problem. Here we report a semi-empirical method that can effectively correct 2D XRF mapping data. The correction error is generally less than 10% from a comprehensive evaluation of the accuracy in various configurations. The proposed method was applied to quantify the composition distribution around the grain boundaries in an electrochemically corroded stainless steel sample. Highly localized Cr enrichment was found around the crack sites, which was invisible before the absorption correction. [ABSTRACT FROM AUTHOR]

B Fabrication of MLL optics. b The MLL optics were fabricated via magnetron sputtering deposition on a silicon substrate and further sectioned by reactive ion etching, followed by focused ion beam (FIB) milling. Discussion and Conclusion The developed monolithic MEMS-based 2D multilayer Laue lens nanofocusing optics significantly simplify the MLLs alignment process and, meanwhile, guarantee the angular and lateral alignment of assembled 2D optics. Keywords: X-ray microscopy; multilayer Laue lenses; optics; MEMS; microfabrication EN X-ray microscopy multilayer Laue lenses optics MEMS microfabrication 28 33 6 11/29/22 20221101 NES 221101 Introduction X-ray microscopy is a powerful characterization tool applied in many scientific fields, such as materials science, environmental science, biology, and energy research [[1]-[4]]. [Extracted from the article]

Abstract: The three-dimensional evolution of nanoligaments of nanoporous gold created by Ag–Au dealloying was studied during isothermal coarsening by X-ray nanotomography and microbeam Laue diffraction. The surface normal orientation, curvature and size of the gold nanoligaments were measured as a function of coarsening time (from 2 to 320min). The following observations were made at 550, 600 and 650°C. First, the distribution of orientations for the surfaces of the nanoligaments becomes more anisotropic with coarsening time, with an increasing area of the surfaces having a low surface energy, consistent with the growth of facets. Second, the curvature distribution of the nanoligaments (scaled by their size) also evolves during coarsening. The evolution of both surface orientation and scaled surface curvature indicates that coarsening does not occur in a self-similar manner, i.e. the interfacial shape distribution of the gold nanoligaments is not self-similar over time as they coarsen. This is consistent with the ligament size not being described by a classical temporal power law for coarsening systems. All three effects, and in particular the increased prevalence of surfaces with a low surface energy at long coarsening times, may affect the surface functionalities and properties of nanoporous gold in various applications, e.g. as catalysts, sensors and actuators. [Copyright &y& Elsevier]

Abstract: In conventional bulk alloy phase diagrams, each discrete composition point is prepared and characterized one at a time, and consequently has a different thermodynamic history. The continuous phase diagram (CPD) offers a unique opportunity to conduct high throughput construction of thin film phase diagram with single universal thermodynamic history applied to all the compositions. Here, we performed the CPD experiment of Fe–Ni–Co ternary alloy system using combinatorial ion beam sputtering system. The high throughput screenings of structural and physical properties were made using scanning microbeam X-ray diffractometer, scanning magneto-optic Kerr effect (SMOKE) measurement, and scanning nano-indentation microscope. The results are consistent with the known structural phases and phase boundaries. In addition, we identified two very narrow amorphous regions, carefully examined and confirmed by synchrotron microbeam X-ray diffraction studies. [Copyright &y& Elsevier]

Advances in nanoscale self-assembly have enabled the formation of complex nanoscale architectures. However, the development of self-assembly strategies toward bottom-up nanofabrication is impeded by challenges in revealing these structures volumetrically at the single-component level and with elemental sensitivity. Leveraging advances in nano-focused hard x-rays, DNA-programmable nanoparticle assembly, and nanoscale inorganic templating, we demonstrate nondestructive three-dimensional imaging of complexly organized nanoparticles and multimaterial frameworks. In a three-dimensional lattice with a size of 2 micrometers, we determined the positions of about 10,000 individual nanoparticles with 7-nanometer resolution, and identified arrangements of assembly motifs and a resulting multimaterial framework with elemental sensitivity. The real-space reconstruction permits direct three-dimensional imaging of lattices, which reveals their imperfections and interfaces and also clarifies the relationship between lattices and assembly motifs. [ABSTRACT FROM AUTHOR]

A self-recording instrument, named Tidal Sediment Dynamics Observational System (TISDOS), was built to monitor transport characteristics of nearbed sediments on tidal flats. It was deployed on a tidal flat in the semi-enclosed Garolim Bay, west coast of Korea, over a 15-day period between 5 and 20 January 2002 to examine sediment-transport processes during winter seasons. The measurements involved brief durations of high waves allowing for observation of wave effects upon the sediment transport on the tidal flat. Time series of various hydrodynamic parameters (water depth, current velocities, wave height, suspended sediment concentration, and bed level) from point measurements show characteristic interrelationships between parameters on both temporal and spatial scales. The tidal flat is dominated by flooding currents up to 2 times stronger than ebb currents. The current speeds measured simultaneously at two stations along a cross-shore transect varied in harmony with water depth, reaching the maximum during spring tide that was steadily decreased onshore. The onshore decrease in current speed was compatible with a fining textural trend from sand on the lower flat to mud toward the upper flat. Both the maximum water depth and current speed during individual tidal cycles also show semi-diurnal asymmetry that was highlighted during spring tide.Waves were of critical importance in resuspending bed material and thus yielding higher suspended sediment concentrations. On the middle flat, the suspended sediment concentrations were highest, exceeding 400 mg/l at 0.5 m above the seabed during large waves (relative wave height, 0.33) under weakest neap currents. In this wavy climate, the suspended sediment concentration increased over time during ebb, in strong contrast with a gradual decrease through time after mid-flood peaks under tidal currents without waves. The daily vertical flux of suspended sediments trapped in a plastic bottle also indicates the significance of wave effects in terms of enhancing resuspension of bottom sediments. As a whole, the suspended silts as well as seabed sands should be transported onshore by dominant flooding currents despite occasional offshore increase in suspension load by waves. [Copyright &y& Elsevier]

Nano-additive aggregation, limited performance, and unclear modification mechanisms are the main obstacles in developing nanocomposite anion exchange membranes (AEMs). In this work, for the first time, an effective and highly stable Poly(vinyl alcohol) (PVA)-based AEMs with dispersive Cu(OH) 2 nanoclusters (Cu-AEMs) are prepared by a simple and eco-friendly three-step method: 'CuCl 2 doping-casting-KOH immersing'. The doped Cu2+ ions chemically combine with OH− ions to form anionic conductive Cu(OH) 2 nanoclusters intermediated by attaching resins. The PVA skeletons wrap around Cu(OH) 2 while the hydroxyl groups expose to bulk water, forming Cu(OH) 2 -PVA complex, which avoids nano-additive aggregation, increases anionic channels, and strengthens additive-matrix connection. A direct borohydride fuel cell using Cu-AEM with 0.56 wt % CuCl 2 possess the highest power density of 403.3 mW cm−2 at 60 °C and a life span of over 200 h. The high-performance and durability come from the unique structure of Cu(OH) 2 nanoclusters-PVA complex. 'Vehicle' theory is considered to be the dominant mechanism for enhancing such nanocomposite Cu-AEMs. This work demonstrates a new concept for preparing the stable AEMs toward high-performance fuel cells. The synthetic chemistry involved can be broadly extended for fabricating versatile AEMs. Image 1 • The dispersive nano-sized Cu(OH) 2 -PVA complex are firstly introduced in AEMs. • Cu2+ combine with PVA, AER, and OH− one by one to form dispersive nano-Cu(OH) 2. • DBFCs using Cu-AEM have high power density (403.3 mW cm−2) and durability (200 h). [ABSTRACT FROM AUTHOR]

Understanding microstructural and strain evolutions induced by noble gas production in the nuclear fuel matrix or plasma-facing materials is crucial for designing next generation nuclear reactors, as they are responsible for volumetric swelling and catastrophic failure. We describe a multimodal approach combining synchrotron-based nanoscale X-ray imaging techniques with atomic-scale electron microscopy techniques for mapping chemical composition, morphology and lattice distortion in a single crystal W induced by Kr irradiation. We report that Kr-irradiated single crystal W undergoes surface deformation, forming Kr containing cavities. Furthermore, positive strain fields are observed in Kr-irradiated regions, which lead to compression of underlying W matrix. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The ever‐increasing brightness of synchrotron radiation sources demands improved X‐ray optics to utilize their capability for imaging and probing biological cells, nano‐devices and functional matter on the nanometre scale with chemical sensitivity. Hard X‐rays are ideal for high‐resolution imaging and spectroscopic applications owing to their short wavelength, high penetrating power and chemical sensitivity. The penetrating power that makes X‐rays useful for imaging also makes focusing them technologically challenging. Recent developments in layer deposition techniques have enabled the fabrication of a series of highly focusing X‐ray lenses, known as wedged multi‐layer Laue lenses. Improvements to the lens design and fabrication technique demand an accurate, robust, in situ and at‐wavelength characterization method. To this end, a modified form of the speckle tracking wavefront metrology method has been developed. The ptychographic X‐ray speckle tracking method is capable of operating with highly divergent wavefields. A useful by‐product of this method is that it also provides high‐resolution and aberration‐free projection images of extended specimens. Three separate experiments using this method are reported, where the ray path angles have been resolved to within 4 nrad with an imaging resolution of 45 nm (full period). This method does not require a high degree of coherence, making it suitable for laboratory‐based X‐ray sources. Likewise, it is robust to errors in the registered sample positions, making it suitable for X‐ray free‐electron laser facilities, where beam‐pointing fluctuations can be problematic for wavefront metrology. [ABSTRACT FROM AUTHOR]

Multi‐slice X‐ray ptychography offers an approach to achieve images with a nanometre‐scale resolution from samples with thicknesses larger than the depth of field of the imaging system by modeling a thick sample as a set of thin slices and accounting for the wavefront propagation effects within the specimen. Here, we present an experimental demonstration that resolves two layers of nanostructures separated by 500 nm along the axial direction, with sub‐10 nm and sub‐20 nm resolutions on two layers, respectively. Fluorescence maps are simultaneously measured in the multi‐modality imaging scheme to assist in decoupling the mixture of low‐spatial‐frequency features across different slices. The enhanced axial sectioning capability using correlative signals obtained from multi‐modality measurements demonstrates the great potential of the multi‐slice ptychography method for investigating specimens with extended dimensions in 3D with high resolution. Combining multi‐slice ptychography with multi‐modality scanning probe microscopy reconstructs two planes of nanostructures separated by 500 nm with sub‐20 nm lateral resolution, assisted by simultaneously measured fluorescence maps for decoupling low‐spatial‐frequency features. [ABSTRACT FROM AUTHOR]

The present study uses nanometer-scale synchrotron X-ray nanofluorescence to investigate season differences in concentrations and distributions of major (Ca, K, S and P) and trace elements (As, Cr, Cu, Fe and Zn) in the root system of Spartina alterniflora collected from Jamaica Bay, New York, in April and September 2015. The root samples were cross-sectioned at a thickness of 10 μm. Selected areas in the root epidermis and endodermis were mapped with a sampling resolution of 100 and 200 nm, varying with the mapping areas. The results indicate that trace element concentrations in the epidermis and endodermis vary among the elements measured, possibly because of their different chemical properties or their ability to act as micronutrients for the plants. Elemental concentrations (As, Ca, Cr, Cu, Fe, K, P, S and Zn) within each individual root sample and between the root samples collected during two different seasons are both significantly different ( p  < 0.01). Furthermore, this study indicates that the nonessential elements (As and Cr) are significantly correlated ( p  < 0.01) with Fe, with high concentrations in the root epidermis, while others are not, implying that Fe may be a barrier to nonessential element transport in the root system. Hierarchy cluster analysis shows two distinct groups, one including As, Cr and Fe and the other the rest of the elements measured. Factor analysis also indicates that the processes and mechanisms controlling element transport in the root system can be different between the nutrient and nonessential elements. [ABSTRACT FROM AUTHOR]

• A machine-learning-based method is developed to automatically measure the small angle between multiple planar surfaces in an interferometer image. • This easy-to-use and accurate method significantly simplifies the angle measurement procedure and is compatible with widely used white light interferometers. • The new method is demonstrated for a quick and precise angle measurement for the alignment of 2D multilayer Laue lenses for developing high-resolution x-ray microscopy. We report a new machine-learning-based approach to automatically measure the small angle between multiple planar surfaces characterized by white light interferometers. By applying an unsupervised clustering algorithm, DBSCAN (Density-Based Spatial Clustering of Applications with Noise), the multiple surfaces in an interferometer image are automatically identified as distinct surfaces. The angles between every two surfaces are then calculated through the surface fitting. This method can be applied to multiple surfaces regardless of their shapes and locations and significantly simplifies the angle measurement procedure. Using the developed method, we have demonstrated a quick and precise angle measurement for the alignment of 2D Multilayer Laue Lenses (MLLs) for the development of high-resolution x-ray microscopy. This automatic, accurate, and robust small-angle measurement method is compatible with widely used white light interferometers and can be further applied to other metrology applications of interferometer results. [ABSTRACT FROM AUTHOR]

• A novel composition of Co 2.4 Sn 0.6 O 4 is prepared using the precipitation method. • The material is synthesized with self-standing nano-rods type morphology. • Co 2.4 Sn 0.6 O 4 anode delivers outstanding electrochemical properties. • The reaction mechanism of Co 2.4 Sn 0.6 O 4 anode is investigated systematically. • Co 2.4 Sn 0.6 O 4 anode has shown high electrochemical performance in sodium-ion full cell. The self-standing nanorod Co 2.4 Sn 0.6 O 4 is synthesized as a high-performance anode material in search of high capacity and stable anode materials for sodium-ion batteries. The Co 2.4 Sn 0.6 O 4 nanorod exhibits a high reversible capacity of 576 mAh g−1 at a current density of 80 mA g−1 and shows excellent high-rate capability. The X-ray absorption spectroscopy study reveals the mechanisms of charge storage reaction and improved cycling performance of Co 2.4 Sn 0.6 O 4. A partially limited conversion reaction of Co– and Sn-oxide during the cycling effectively regulate the irreversible capacity loss over the cycling that is commonly observed from the conversion and alloying reaction-based anode materials. Furthermore, Co 2.4 Sn 0.6 O 4 also exhibits superior sodium-ion full cell performance when coupled with a NaNi 2/3 Bi 1/3 O 2 cathode, demonstrating an energy density of 262 Wh kg−1. [ABSTRACT FROM AUTHOR]

Abstract: Microstructural evolution in solid oxide fuel cell (SOFC) cermet anodes has been investigated using X-ray nanotomography along with differential absorption imaging. SOFC anode supports composed of Ni and yttria-stabilized zirconia (YSZ) were subjected to extended operation and selected regions were imaged using a transmission X-ray microscope. X-ray nanotomography provides unique insight into microstructure changes of all three phases (Ni, YSZ, pore) in three spatial dimensions, and its relation to performance degradation. Statistically significant 3D microstructural changes were observed in the anode Ni phase over a range of operational times, including phase size growth and changes in connectivity, interfacial contact area and contiguous triple-phase boundary length. These observations support microstructural evolution correlated to SOFC performance. We find that Ni coarsening is driven by particle curvature as indicated by the dihedral angles between the Ni, YSZ and pore phases, and hypothesize that growth occurs primarily by means of diffusion and particle agglomeration constrained by a pinning mechanism related to the YSZ phase. The decrease in Ni phase size after extended periods of time may be the result of a second process connected to a mobility-induced decrease in the YSZ phase size or non-uniform curvature resulting in a net decrease in Ni phase size. [Copyright &y& Elsevier]

Abstract: We report the basic beamline design and current status of a new full-field X-ray imaging facility at Sector 32 of the Advanced Photon Source. The beamline consists of an existing hutch at 40m and a new experiment enclosure at 77m from the source, with both monochromatic and white-beam undulator X-ray capabilities. Experimental programs being planned for the beamline include high-speed time-resolved imaging, phase-contrast and coherent imaging, diffraction-enhanced imaging, ultra-small-angle scattering imaging, and phase- and absorption-contrast transmission X-ray microscopy. [Copyright &y& Elsevier]

The focusing property of an ellipsoidal monocapillary has been characterized using the ptychography method with a 405 nm laser beam. The recovered wavefront gives a 12.5 × 10.4 μ m 2 focus. The reconstructed phase profile of the focused beam can be used to estimate the height error of the capillary surface. The obtained height error shows a Gaussian distribution with a standard deviation of 1.3 μ m. This approach can be used as a quantitative tool for evaluating the inner functional surfaces of reflective optics, complementary to conventional metrology methods. [ABSTRACT FROM AUTHOR]

Scientists have long suspected that compositionally zoned particles can form under far-from equilibrium precipitation conditions, but their inferences have been based on bulk solid and solution measurements. We are the first to directly observe nanoscale trace element compositional zonation in <10 µm-sized particles using X-ray fluorescence nanospectroscopy at the Hard X-ray Nanoprobe (HXN) Beamline at National Synchrotron Light Source II (NSLS-II). Through high-resolution images, compositional zonation was observed in barite (BaSO4) particles precipitated from aqueous solution, in which Sr2+ cations as well as HAsO42− anions were co-precipitated into (Ba,Sr)SO4 or Ba(SO4,HAsO4) solid solutions. Under high salinity conditions (NaCl ≥ 1.0 M), bands contained ~3.5 to ~5 times more trace element compared to the center of the particle formed in early stages of particle growth. Quantitative analysis of Sr and As fractional substitution allowed us to determine that different crystallographic growth directions incorporated trace elements to different extents. These findings provide supporting evidence that barite solid solutions have great potential for trace element incorporation; this has significant implications for environmental and engineered systems that remove hazardous substances from water. [ABSTRACT FROM AUTHOR]

Single impurities in insulators are now often used for quantum sensors and single photon sources, while nanoscale semiconductor doping features are being constructed for electrical contacts in quantum technology devices, implying that new methods for sensitive, non-destructive imaging of single- or few-atom structures are needed. X-ray fluorescence (XRF) can provide nanoscale imaging with chemical specificity, and features comprising as few as 100 000 atoms have been detected without any need for specialized or destructive sample preparation. Presently, the ultimate limits of sensitivity of XRF are unknown - here, gallium dopants in silicon are investigated using a high brilliance, synchrotron source collimated to a small spot. It is demonstrated that with a single-pixel integration time of 1 s, the sensitivity is sufficient to identify a single isolated feature of only 3000 Ga impurities (a mass of just 350 zg). With increased integration (25 s), 650 impurities can be detected. The results are quantified using a calibration sample consisting of precisely controlled numbers of implanted atoms in nanometer-sized structures. The results show that such features can now be mapped quantitatively when calibration samples are used, and suggest that, in the near future, planned upgrades to XRF facilities might achieve single-atom sensitivity., (© 2024 The Authors. Small Methods published by Wiley‐VCH GmbH.)

Magnetic nanomaterials are sought to provide new functionalities for applications ranging from information processing and storage to energy generation and biomedical imaging. MXenes are a rapidly growing family of two-dimensional transition metal carbides and nitrides with versatile chemical and structural diversity, resulting in a variety of interesting electronic and optical properties. However, strategies for producing MXenes with tailored magnetic responses remain underdeveloped and challenging. Herein, we incorporate elemental Ni and Co into Ti 3 C 2 T x MXene by mixing with dilute metal chloride solutions. We achieve a uniform distribution of Ni and Co, confirmed by X-ray fluorescence (XRF) mapping with nanometer resolution, with Ni and Co concentrations of approximately 2 and 7 at% relative to the Ti concentration. The magnetic susceptibility of these Ni- and Co-incorporated Ti 3 C 2 T x MXenes is one to two orders of magnitude larger than pristine Ti 3 C 2 T x , illustrating the potential for dilute metal incorporation to enhance linear magnetic responses at room temperature.

X-ray computed tomography (XCT) and X-ray fluorescence (XRF) imaging are two non-invasive imaging techniques to study cellular structures and chemical element distributions, respectively. However, correlative X-ray computed tomography and fluorescence imaging for the same cell have yet to be routinely realized due to challenges in sample preparation and X-ray radiation damage. Here we report an integrated experimental and computational workflow for achieving correlative multi-modality X-ray imaging of a single cell. The method consists of the preparation of radiation-resistant single-cell samples using live-cell imaging-assisted chemical fixation and freeze-drying procedures, targeting and labeling cells for correlative XCT and XRF measurement, and computational reconstruction of the correlative and multi-modality images. With XCT, cellular structures including the overall structure and intracellular organelles are visualized, while XRF imaging reveals the distribution of multiple chemical elements within the same cell. Our correlative method demonstrates the feasibility and broad applicability of using X-rays to understand cellular structures and the roles of chemical elements and related proteins in signaling and other biological processes., (© 2024. The Author(s).)

Coal combustion byproducts are known to be enriched in arsenic (As) and selenium (Se). This enrichment is a concern during the handling, disposal, and reuse of the ash as both elements can be harmful to wildlife and humans if mobilized into water and soils. The leaching potential and bioaccessibility of As and Se in coal fly ash depends on the chemical forms of these elements and their association with the large variety of particles that comprise coal fly ash. The overall goal of this research was to determine nanoscale and microscale solid phase mineral associations and oxidation states of As and Se in fly ash. We utilized nanoscale 2D imaging (30-50 nm spot size) with the Hard X-ray Nanoprobe (HXN) in combination with microprobe X-ray capabilities (∼5 μm resolution) to determine the As and Se elemental associations. Speciation of As and Se was also measured at the nano- to microscale with X-ray absorption spectroscopy. The enhanced resolution of HXN showed As and Se as either diffusely located around or comingled with Ca- and Fe-rich particles. The results also showed nanoparticles of Se attached to the surface of fly ash grains. Overall, a comparison of As and Se species across scales highlights the heterogeneity and complexity of chemical associations for these trace elements of concern in coal fly ash., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Understanding the nanoscale chemical speciation of heterogeneous systems in their native environment is critical for several disciplines such as life and environmental sciences, biogeochemistry, and materials science. Synchrotron-based X-ray spectromicroscopy tools are widely used to understand the chemistry and morphology of complex material systems owing to their high penetration depth and sensitivity. The multidimensional (4D+) structure of spectromicroscopy data poses visualization and data-reduction challenges. This paper reports the strategies for the visualization and analysis of spectromicroscopy data. We created a new graphical user interface and data analysis platform named XMIDAS (X-ray multimodal image data analysis software) to visualize spectromicroscopy data from both image and spectrum representations. The interactive data analysis toolkit combined conventional analysis methods with well-established machine learning classification algorithms (e.g. nonnegative matrix factorization) for data reduction. The data visualization and analysis methodologies were then defined and optimized using a model particle aggregate with known chemical composition. Nanoprobe-based X-ray fluorescence (nano-XRF) and X-ray absorption near edge structure (nano-XANES) spectromicroscopy techniques were used to probe elemental and chemical state information of the aggregate sample. We illustrated the complete chemical speciation methodology of the model particle by using XMIDAS. Next, we demonstrated the application of this approach in detecting and characterizing nanoparticles associated with alveolar macrophages. Our multimodal approach combining nano-XRF, nano-XANES, and differential phase-contrast imaging efficiently visualizes the chemistry of localized nanostructure with the morphology. We believe that the optimized data-reduction strategies and tool development will facilitate the analysis of complex biological and environmental samples using X-ray spectromicroscopy techniques., (© The Author(s) 2022. Published by Oxford University Press.)

High-capacity Ni-rich layered oxides are promising cathode materials for secondary lithium-based battery systems. However, their structural instability detrimentally affects the battery performance during cell cycling. Here, we report an Al/Zr co-doped single-crystalline LiNi 0.88 Co 0.09 Mn 0.03 O 2 (SNCM) cathode material to circumvent the instability issue. We found that soluble Al ions are adequately incorporated in the SNCM lattice while the less soluble Zr ions are prone to aggregate in the outer SNCM surface layer. The synergistic effect of Al/Zr co-doping in SNCM lattice improve the Li-ion mobility, relief the internal strain, and suppress the Li/Ni cation mixing upon cycling at high cut-off voltage. These features improve the cathode rate capability and structural stabilization during prolonged cell cycling. In particular, the Zr-rich surface enables the formation of stable cathode-electrolyte interphase, which prevent SNCM from unwanted reactions with the non-aqueous fluorinated liquid electrolyte solution and avoid Ni dissolution. To prove the practical application of the Al/Zr co-doped SNCM, we assembled a 10.8 Ah pouch cell (using a 100 μm thick Li metal anode) capable of delivering initial specific energy of 504.5 Wh kg -1 at 0.1 C and 25 °C., (© 2022. The Author(s).)

Single-crystalline nickel-rich cathodes are a rising candidate with great potential for high-energy lithium-ion batteries due to their superior structural and chemical robustness in comparison with polycrystalline counterparts. Within the single-crystalline cathode materials, the lattice strain and defects have significant impacts on the intercalation chemistry and, therefore, play a key role in determining the macroscopic electrochemical performance. Guided by our predictive theoretical model, we have systematically evaluated the effectiveness of regaining lost capacity by modulating the lattice deformation via an energy-efficient thermal treatment at different chemical states. We demonstrate that the lattice structure recoverability is highly dependent on both the cathode composition and the state of charge, providing clues to relieving the fatigued cathode crystal for sustainable lithium-ion batteries., (© 2022. The Author(s).)

Mechanical integrity issues such as particle cracking are considered one of the leading causes of structural deterioration and limited long-term cycle stability for Ni-rich cathode materials of Li-ion batteries. Indeed, the detrimental effects generated from the crack formation are not yet entirely addressed. Here, applying physicochemical and electrochemical ex situ and in situ characterizations, the effect of Co and Mn on the mechanical properties of the Ni-rich material are thoroughly investigated. As a result, we successfully mitigate the particle cracking issue in Ni-rich cathodes via rational concentration gradient design without sacrificing the electrode capacity. Our result reveals that the Co-enriched surface design in Ni-rich particles benefits from its low stiffness, which can effectively suppress the formation of particle cracking. Meanwhile, the Mn-enriched core limits internal expansion and improve structural integrity. The concentration gradient design also promotes morphological stability and cycling performances in Li metal coin cell configuration., (© 2021. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Zeolites are three-dimensional aluminosilicates having unique properties from the size and connectivity of their sub-nanometer pores, the Si/Al ratio of the anionic framework, and the charge-balancing cations. The inhomogeneous distribution of the cations affects their catalytic performances because it influences the intra-crystalline diffusion rates of the reactants and products. However, the structural deformation regarding inhomogeneous active regions during the catalysis is not yet observed by conventional analytical tools. Here we employ in situ X-ray free electron laser-based time-resolved coherent X-ray diffraction imaging to investigate the internal deformations originating from the inhomogeneous Cu ion distributions in Cu-exchanged ZSM-5 zeolite crystals during the deoxygenation of nitrogen oxides with propene. We show that the interactions between the reactants and the active sites lead to an unusual strain distribution, confirmed by density functional theory simulations. These observations provide insights into the role of structural inhomogeneity in zeolites during catalysis and will assist the future design of zeolites for their applications.

Quasi-two-dimensional (quasi-2D) materials hold promise for future electronics because of their unique band structures that result in electronic and mechanical properties sensitive to crystal strains in all three dimensions. Quantifying crystal strain is a prerequisite to correlating it with the performance of the device and calls for high resolution but spatially resolved rapid characterization methods. Here, we show that using fly-scan nano X-ray diffraction, we can accomplish a tensile strain sensitivity below 0.001% with a spatial resolution of better than 80 nm over a spatial extent of 100 μm on quasi-2D flakes of 1T-TaS 2 . Coherent diffraction patterns were collected from a ∼100 nm thick sheet of 1T-TaS 2 by scanning a 12 keV focused X-ray beam across and rotating the sample. We demonstrate that the strain distribution around micron- and submicron-sized "bubbles" that are present in the sample may be reconstructed from these images. The experiments use state-of-the-art synchrotron instrumentation and will allow rapid and nonintrusive strain mapping of thin-film samples and electronic devices based on quasi-2D materials.

The development of membranes with low fuel crossover and high fuel efficiency is a key issue in direct borohydride fuel cells (DBFCs). In previous work, we produced a poly(vinyl alcohol) (PVA)-anion-exchange resin (AER) membrane with a low fuel crossover and a low fuel efficiency by introducing Co ions. In this work, a bilayer membrane was designed to improve the fuel efficiency and cell performance. The bilayer membrane was prepared by casting a PVA-AER wet gel onto the partially desiccated Co-PVA-AER gel. The bilayer membrane showed a borohydride permeability of 1.34 × 10 -6 cm 2 ·s -1 , which was even lower than that of the Co-PVA-AER membrane (1.98 ×10 -6 cm 2 ·s -1 ) and the PVA-AER membrane (2.80 × 10 -6 cm 2 ·s -1 ). The DBFC using the bilayer membrane exhibited a higher fuel efficiency (37.4%) and output power (1.73 Wh) than the DBFCs using the Co-PVA-AER membrane (33.3%, 1.27 Wh) and the PVA-AER membrane (34.3%, 1.2 Wh). Furthermore, the DBFC using the bilayer membrane achieved a peak power density of 327 mW·cm -2 , which was 2.14 times of that of the DBFC using the PVA-AER membrane (153 mW·cm -2 ). The drastic improvement benefited from the bilayer design, which introduced an interphase to suppress fuel crossover and avoided unnecessary borohydride hydrolysis.

We report on the development of 2D integrated multilayer Laue lens (MLL) nanofocusing optics used for high-resolution x-ray microscopy. A Micro-Electro-Mechanical-Systems (MEMS) - based template has been designed and fabricated to accommodate two linear MLL optics in pre-aligned configuration. The orthogonality requirement between two MLLs has been satisfied to a better than 6 millidegrees level, and the separation along the x-ray beam direction was controlled on a micrometer scale. Developed planar 2D MLL structure has demonstrated astigmatism free point focus of ∼14 nm by ∼13 nm in horizontal and vertical directions, respectively, at 13.6 keV photon energy. Approaching 10 nm resolution with integrated 2D MLL optic is a significant step forward in applications of multilayer Laue lenses for high-resolution hard x-ray microscopy and their adoption by the general x-ray microscopy community.