We report the commissioning of a multimodal computed tomography experimental setup at the 28-ID-2 (XPD) beamline of the National Synchrotron Light Source II. This high-energy (>60 keV) resource features a tunable X-ray beam size ranging from several millimetres to a few micrometres and enables comprehensive characterization of high-Z materials—an essential capability for nuclear and advanced materials research. It provides four complementary computed tomography modalities: X-ray absorption, X-ray fluorescence, X-ray diffraction, and pair distribution function tomography. A case study using a custom-made heterogeneous sample demonstrates these abilities to simultaneously capture atomic, elemental, and morphological information. This unique combination of imaging, structural, and chemical sensitive methods provides a holistic approach to study complex materials with amorphous and crystalline systems across multiple length scales.

Manmade detention ponds have historically been impacted by anthropogenic activities such as rainwater runoff, car emissions, and drainage from infrastructures, which can lead to complications for pond ecosystems. Sediment samples collected from the northern, southern, western, and eastern regions of a small pond on a suburban high school campus on Long Island, NY, were analyzed for potential chemical changes resulting from an inundation of water by a broken water main. Incorporating synchrotron X-ray techniques, sediment was analyzed using Submicron Resolution Spectroscopy, Tender Energy X-ray Spectroscopy, and X-ray Powder Diffraction to examine heavy metals, light elements, and minerals. Results include a Zn:Cu ratio increase from 4:1 to 10:1 in the eastern zone and a higher heavy metal presence in the western zone for all elements examined, with greater distribution throughout the pond post-inundation. Lighter elements appear to remain relatively unchanged. The appearance of diopside in the eastern zone post-inundation samples suggests contamination from the water main break, while the presence of carbonate minerals in the western zone is consistent with erosion of asphalt material from the adjacent parking lot.

Mudrocks and mud-sized sediments (i.e., silt to clay) dominate the surface of Earth and Mars. These fine-grained sediments preserve a rich history of sedimentary processes from source to sink and shed light on ancient climates. However, both the physical and chemical nature of these materials make them difficult to fully characterize with traditional laboratory techniques. Here, we explore a cross-disciplinary and high-resolution approach using synchrotron radiation for X-ray diffraction, pair distribution function analysis, and submicrometer-scale X-ray fluorescence, combined with transmission electron microscopy, to better understand the nanostructure and composition of mud-sized sediments from a glacio-fluvial watershed in southwest Iceland. Our results demonstrate that sediments in the cold and wet climate of Iceland are more altered than previously thought, as evidenced by the identification of kaolinite and mixed-layer kaolinite-smectite. Additionally, sediments are enriched in amorphous materials and nanocrystalline phases, as determined from grain morphologies and compositions consistent with allophane, hisingerite, ferrihydrite, and halloysite. These alteration products are present as intimate mixtures that vary across depositional sites, demonstrating the dynamic nature of the secondary assemblage from source to sink. This work has implications for Mars, where, for example, basalt-sourced sedimentary rocks from Gale crater are abundant in clay minerals and amorphous materials. Finally, this work underpins the importance of using high-resolution techniques, a coordinated methodology, and developing innovative approaches for future planetary sample return missions (e.g., Mars sample return).

Anionic complexes having vapochromic behavior are investigated: [K(H2O)][M(ppy)(CN)2], [K(H2O)][M(bzq)(CN)2], and [Li(H2O)n][Pt(bzq)(CN)2], where ppy = 2-phenylpyridinate, bzq = 7,8-benzoquinolate, and M = Pt(II) or Pd(II). These hydrated potassium/lithium salts exhibit a change in color upon being heated to 380 K, and they transform back into the original color upon absorption of water molecules from the environment. The challenging characterization of their structure in the vapochromic transition has been carried out by combining several experimental techniques, despite the availability of partially ordered and/or impure crystalline material. Room-temperature single-crystal and powder X-ray diffraction investigation revealed that [K(H2O)][Pt(ppy)(CN)2] crystallizes in the Pbca space group and is isostructural to [K(H2O)][Pd(ppy)(CN)2]. Variable-temperature powder X-ray diffraction allowed the color transition to be related to changes in the diffraction pattern and the decrease in sample crystallinity. Water loss, monitored by thermogravimetric analysis, occurs in two stages, well separated for potassium Pt compounds and strongly overlapped for potassium Pd compounds. The local structure of potassium compounds was monitored by in situ pair distribution function (PDF) measurements, which highlighted changes in the intermolecular distances due to a rearrangement of the crystal packing upon vapochromic transition. A reaction coordinate describing the structural changes was extracted for each compound by multivariate analysis applied to PDF data. It contributed to the study of the kinetics of the structural changes related to the vapochromic transition, revealing its dependence on the transition metal ion. Instead, the ligand influences the critical temperature, higher for ppy than for bzq, and the inclination of the molecular planes with respect to the unit cell planes, higher for bzq than for ppy. The first stage of water loss triggers a unit cell contraction, determined by the increase in the b axis length and the decrease in the a (for ppy) or c (for bzq) axis lengths. Consequent interplane distance variations and in-plane roto-translations weaken the π-stacking of the room-temperature structure and modify the distances and angles of Pt(II)/Pd(II) chains. The curve describing the intermolecular Pt(II)/Pd(II) distances as a function of temperature, validated by X-ray absorption spectroscopy, was found to reproduce the coordinate reaction determined by the model-free analysis.

Here, we present an automated and rapid method for nondestructive mapping of crystal grains in a rod-shaped sample. The approach was designed for application to in situ float-zone crystal growth experiments at an X-ray synchrotron source but could be useful in other applications. The methods have been tested on a TiO2 boule grown in an optical float-zone furnace. The approach applies a statistical filter to polycrystalline diffraction patterns on two-dimensional (2D) detectors to rapidly determine the degree of powder quality of the signal. When larger crystals emerge in the growth, their position, size, and shape can be tracked using an automated blob-tracking algorithm that follows individual Bragg peaks as a function of position in a grid scan, even when multiple crystals are contributing spots to diffraction images. This method is found to be robust as the same crystal shape can be independently reconstructed using different sets of Bragg reflections. Image segmentation methods are then used to map out the polycrystalline grains. We also note that other information about crystal quality, such as mosaicity or strain state, may be inferred and mapped from the intensity variation of the Bragg peaks at different locations within the sample.

The hierarchical nature of additively manufactured materials necessitates a multimodal approach for quantifying microstructural features and corresponding chemical heterogeneities that ultimately impact their properties and performance. In laser powder-bed fusion (L-PBF) 316L stainless steel, corrosion behavior has been discussed in the context of chemical heterogeneities formed in the presence of these hierarchical microstructures. Here, we employ a suite of advanced synchrotron x-ray techniques and correlative transmission electron microscopy for the analysis of microstructure and chemical heterogeneities in L-PBF 316L as a function of printing speed. Our findings reveal an appreciable dislocation density consistent with the formation of a cellular dislocation microstructure in L-PBF 316L, which is correlated to spatial variations in the local Cr concentration and the formation of complex Mn7C3 nanoinclusions. Cyclic voltammetry experiments reveal that relative to wrought 316L, the printed samples exhibit either a comparable or marginally reduced susceptibility to uniform corrosion but with an increased affinity for pitting particularly in the samples printed at the highest speed with the largest dislocation density. Given the spatial correlations between regions of high dislocation density and the formation of chemical heterogeneities known to degrade corrosion performance, our findings demonstrate the impact of the microstructural defect state and its variation with printing speed on the resistance of L-PBF 316L to uniform and localized corrosion.

The ability of optical floating zone (OFZ) furnaces to rapidly produce large single crystals of complex emerging materials has had a transformative effect on many scientific fields that require samples of this type. However, the crystal growth process within the OFZ furnace is not well understood owing to the challenges involved in monitoring the high-temperature crystal growth process. Novel beamline-compatible optical furnaces that approximate the inhomogeneous growth environment within an OFZ furnace have been fabricated and tested in high-energy synchrotron beamlines. It is demonstrated that temperature profiles can be effectively extracted from powder diffraction data collected on polycrystalline ceramic rods heated at their tip. Furthermore, these measured temperature profiles can be accurately reproduced using a heattransfer model that accounts for solid-state thermal conduction, partial sample lamp power absorption, convective air cooling and radiative cooling, allowing key thermal parameters such as thermal conductivity to be extracted from experimental data.

Brookhaven National Laboratory (New York) launched its high-energy X-ray science program at the inception of the National Synchrotron Light Source (NSLS), a U.S. Department of Energy (DOE) Office o...

Additive manufacturing (AM) of alloys such as stainless steels has the potential to be a disruptive technology for design of complex structures which eliminates the potentially damaging effects of mechanical failure and localized corrosion associated with interfaces between separate parts (which can now be printed as part of a single assembly). In addition, increasingly complex geometries can be manufactured with nearly as much ease as simple ones, and new mechanisms for optimization and generative design can allow manufacturers to achieve significant material and weight savings. However, challenges remain, in particular due to the potential for material variabilities both between parts made with the same nominal build parameters and even within a single build, as the consistency in properties inherent in the commercial-scale forging of alloys to be machined into components is exchanged for the considerable advantages of on-site, distributed custom parts production. Our studies and related work by other groups indicates that this is clearly true in the case of corrosion susceptibility in AM alloys. By studying the relationship between build parameters and electrochemical properties, we propose that it will be possible to tailor alloys for enhanced corrosion properties. AM processes produce materials with hierarchical microstructures containing fusion boundaries at the macroscale, irregular grains and grain boundaries at the microscale, and subgrain dislocation structures at the nanoscale. In laser powder bed fusion (LPBF) formed 316L stainless steel structures, corrosion performance has been discussed in the context of chemical heterogeneities formed in the presence of these hierarchical microstructures. However, the large variability in reported measurements underscores the need for statistically significant microstructural data, which is often difficult to access via electron microscopy alone. In this presentation, we explore multi-modal synchrotron X-ray techniques for quantifying hierarchical microstructures and their connection to the underlying chemical distribution in 316L stainless steel. Our results show that the dislocation density depends on the printing conditions with implications for the chemical distribution at the nanoscale, which in turn may play a key role in inconsistent corrosion behavior. LPDF 316L samples formed at varying speeds using pulsed and continuous laser deposition are compared via cyclic polarization in 3.5% NaCl and 0.1M HCl solutions, as well as using standard methods for characterizing sensitization. Surface corrosion layers are characterized using laboratory-based X-ray photoelectron spectroscopy to determine the impact on passivity of the aforementioned microsegregation associated with process-induced microstructures. Corrosion rates and pit densities are then discussed to build a connection between printing conditions and corrosion performance vis-à-vis microstructural and chemical information from synchrotron measurements performed at Brookhaven National Laboratory (BNL), including high energy X-ray diffraction using the X-ray Powder Diffraction (XPD) beamline at the National Synchrotron Light Source-II (NSLS-II) which provided data on minor precipitate population(s), atomic structure and dislocation microstructures critical to corrosion behavior. In addition, heterogeneities in elemental composition data is provided by 2D X-ray fluorescence (XRF) and 2D X-ray Absorption Spectroscopy (XAS) nanometer resolution-mapping obtained at the Hard X-ray Nanoprobe (HXN) beamline at the NSLS-II and correlated with process-induced hierarchal structures via use of the microscopy facilities at the Center for Functional Nanomaterials (CFN). By employing a combination of multi-modal synchrotron characterization techniques, electron microscopy, and baseline testing protocol combined with electrochemical polarization experiments, we are able to study the the role of microstructure across multiple length scales on electrochemical properties and corrosion performance. Understanding the impact of microstructure and chemical heterogeneities on the susceptibility to pitting and intergranular attack will enable microstructurally-informed process optimization and materials design for enhancing the corrosion resistance of LPBF 316L stainless steel, with implications for AM and subsequent durability of alloys in general.

The combination of the multi-modal synchrotron approach and data analytics furthers the understanding of the electrochemically-driven phase-transformation of TiS2in Na-ion batteries.

In chemical reactions, the breaking and formation of chemical bonds usually need external energy to overcome the activation barriers. Conventional energy delivery transfers energy from heating sources via various media, hence losing efficiency and inducing side reactions. In contrast, microwave (MW) heating is known to be highly energy efficient through dipole interaction with polar media, but how exactly it transmits energy to initiate chemical reactions has been unknown. Here, we report a rigorous determination of energy delivery mechanisms underlying MW-enabled rapid hydrothermal synthesis, by monitoring the structure and temperature of all the involved components as solid-liquid intercalation reaction occurs using in situ synchrotron techniques. We reveal a hitherto unknown direct energy transmission between MW irradiation source and the targeted reactants, leading to greatly reduced energy waste, and so the ultrafast kinetics at low temperature. These findings open up new horizons for designing material synthesis reactions of high efficiency and precision.

Multimodal Synchrotron Approach: Research Needs and Scientific Vision Yu-Chen Karen Chen-Wiegart, Iradwikanari Waluyo, Andrew Kiss, Stuart Campbell, Lin Yang, Eric Dooryhee, Jason R. Trelewicz, Yiyang Li, Bruce Gates, Mark Rivers & Kevin G. Yager To cite this article: Yu-Chen Karen Chen-Wiegart, Iradwikanari Waluyo, Andrew Kiss, Stuart Campbell, Lin Yang, Eric Dooryhee, Jason R. Trelewicz, Yiyang Li, Bruce Gates, Mark Rivers & Kevin G. Yager (2020) Multimodal Synchrotron Approach: Research Needs and Scientific Vision, Synchrotron Radiation News, 33:1, 44-47, DOI: 10.1080/08940886.2020.1701380 To link to this article: https://doi.org/10.1080/08940886.2020.1701380

RMD @ NSLS-II helps pave the path to a DMMSC: Developing expertise in techniques and experimental methods for DMMSC science; Improving capabilities for models to become microstructurally aware; Workforce training and development; Help refine DMMSC scientific requirements; Complementary to DMMSC XFEL science (EDXD/EXAFS)

Li1.1V3O8 (LVO) has shown promise as a cathode material for lithium-based batteries due to its high theoretical capacity (360 mAh.g(-1)) and good rate capability; however, LVO batteries suffer from capacity fade upon extended cycling. The impact of synthetic material control on electrochemistry and capacity retention was explored through solvothermal synthesis of LVO fibers and sol-gel synthesis of LVO rhombohedrons. Cyclic voltammetry (CV) of the twomaterials revealed key differences where lithiation of the solvothermal-derived LVO material resulted in less beta phase formation as compared with the sol-gel-derived material. Structural evolution of the materials during lithiation was characterized through in situ XRD which revealed that the alpha ->beta phase conversion is essentially complete in the sol-gel product with only partial conversion in the solvothermal product. Under galvanostatic cycling, the sol-gel product delivered higher capacity but displayed more capacity fade as compared to the solvothermal product as foretold by both CV and XRD findings. When cycled within the a phase region, improved preservation of both energy delivery and structural integrity was observed. These findings substantiate the proposed cause of capacity degradation as originating from an alpha ->beta structural change and illustrate the possibility of minimizing alpha ->beta phase formation through synthetic control of LVO. (C) 2019 The Electrochemical Society.

Transition metal layered oxides have been the dominant cathodes in lithium-ion batteries, and among them, high-Ni ones (LiNixMnyCozO2; x >= 0.7) with greatly boosted capacity and reduced cost are of particular interest for large-scale applications. The high Ni loading, on the other hand, raises the critical issues of surface instability and poor rate performance. The rational design of synthesis leading to layered LiNi0.7Mn0.15Co0.15O2 with greatly enhanced rate capability is demonstrated, by implementing a quenching process alternative to the general slow cooling. In situ synchrotron X-ray diffraction, coupled with surface analysis, is applied to studies of the synthesis process, revealing cooling-induced surface reconstruction involving Li2CO3 accumulation, formation of a Li-deficient layer and Ni reduction at the particle surface. The reconstruction process occurs predominantly at high temperatures (above 350 degrees C) and is highly cooling-rate dependent, implying that surface reconstruction can be suppressed through synthetic control, i.e., quenching to improve the surface stability and rate performance of the synthesized materials. These findings may provide guidance to rational synthesis of high-Ni cathode materials.

High-nickel layered oxides are promising cathode candidates for high energy density Li-ion batteries. However, as Ni loading increases, synthetic control of structure/stoichiometry, especially at the surface, becomes a challenge. The work presented in article number 1901915 by Jianming Bai, Feng Pan, Feng Wang, and co-workers, through in situ X-ray study into the synthesis of LiNi0.7Mn0.15Co0.15O2 coupled with surface analysis, reveals cooling-induced surface reconstruction, thereby enabling rational design of synthesis to improve the surface properties of synthesized materials.

Since the first report of the inserting reaction of alkali metals in layered dichalcogenides in 1959, titanium disulfide (TiS2) has been widely studied as a model material of intercalation host compound in energy storage for Li-ion batteries. Due to its high electric conductivity, fast rate capability, good cycling performance and natural abundance, TiS2 electrode also became a promising candidate for the low-cost Na-ion battery system. However, the differences regarding the detailed chemical and structural evolutions and reaction mechanism of TiS2 in Li-ion and Na-ion batteries are not yet well understood. In this work, the chemical and structural evolutions of TiS2 in both Li-ion and Na-ion batteries are investigated via operando synchrotron absorption spectroscopy (XAS) at both the sulfur and titanium K-edges using complementary hard x-rays and tender x-rays at the National Synchrotron Light Source II. By combining X-ray diffraction and operando XAS with the Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) method, we reveal the chemical speciation during the electrochemical cycling. Our study also sheds light on the reaction mechanism of Na-TiS2, which is compared with that of the Li-TiS2 system. ACKNOWLEDGMENT We thank DOE Office of Energy Efficiency and Renewable Energy under the Advanced Battery Materials Research (BMR) program, Contract No. DE-SC0012704; we thank ISS, TES, and XPD beamlines of NSLS-II, supported by DOE Office of Science. This research used resources of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704. Funding was supported by Stony Brook University and Brookhaven National Laboratory. Figure: An illustration of the structural and chemical evolutions during sodiaiton observed by operando XAS and ex situ XPD approaches. Figure 1

The exact recipe to prepare the ancient Maya Blue (MB), an incredibly resistant and brilliant pigment prepared from indigo (dye) and Palygorskite (clay), is lost to the ages. To unravel the key features of the MB formation process, several inorganic-dye couples were heated to 200 degrees C and cooled to RT, to investigate their reactivity and the diffusion and degree of sequestration of the dye into the inorganic host. In situ XRPD/PDF and fiber optic reflectance spectroscopy (FORS) data, along with TGA, provided a comprehensive overview on MB formation mechanism. XRPD/PDF gave information on long/short range behaviors of water desorption/adsorption and indigo sequestration, while TGA and in situ FORS gave information on mass and optical changes within temperature. Ex situ dye removal was used to understand the sample stability after the thermal treatment. A statistical approach based on principal component analysis was exploited to efficiently and jointly analyze the approximate to 3000 collected patterns. MB formation starts below 110 degrees C with disordered distribution of indigo within the channels, reaching maximum reaction speed and higher ordering at 150 degrees C. Above 175 degrees C, color changes and a stronger sequestration of indigo into framework channels are observed, whereas the affinity for water is dramatically reduced. The origin of different colors, hues, and stability in historical MB samples can then be explained in terms of different thermal histories of the starting mechanical indigo/palygorskite mixtures.