Synchrotron Radiation X-ray Research Articles

Two types of cubic components coexisting in the paraelectric phase of relaxor ferroelectric Pb(Mg1/3Nb2/3)O3 revealed by synchrotron radiation X-ray diffraction

The crystal structures of relaxor ferroelectric Pb(Mg1/3Nb2/3)O3 (PMN) have been investigated using synchrotron radiation X-ray powder diffraction. Two different types of cubic components coexist in the paraelectric phase at 600 K. The first is Cubic-I, in which the Pb ion is isotropically off-centered from the corner of the perovskite-type unit cell. The other, Cubic-II, has the Pb ion preferentially off-centered in the <111> directions from the corner. The volume fractions of Cubic-I and Cubic-II are approximately 83% and 17%, respectively. Previous studies have shown that only approximately 20% of PMN transitions to a rhombohedral structure at 100 K. This observation suggests a close relationship between Cubic-II and the rhombohedral structure at low temperatures. The intrinsic structural inhomogeneity observed in the paraelectric phase, such as variations in the disordering behavior of Pb ions, is potentially linked to the relaxor characteristics of PMN.

Utilizing acid-etched Fe-waste for sustainable synthesis of conductive perovskite-type materials from automotive industrial residue

A common method for reducing waste and environmental problems brought on by landfills is to reuse waste, especially heavy metals such as iron. Automotive industrial waste containing Fe-rich metal is successfully transformed into a highly pure structure of Fe2O3 using an etching method with HNO3 acid. This resulting structure serves as a precursor for synthesizing LaNi1-xFexO3±δ perovskite conducting materials. The desired perovskite conductive phase can be produced by substituting Fe2O3-treated waste at the B-site (Ni position) before calcination at 1200 °C. However, LaNiO3±δ and LaNi0.6Fe0.4O3±δ could not be synthesized under ideal conditions, as indicated by XRD analysis using TOPAS software, which revealed the presence of undesirable phases. Both compounds, LaNiO3±δ and LaNi0.6Fe0.4O3±δ demonstrated electrical conductivity with values of 362 S/cm and 42 S/cm at 550 °C, respectively. Nonetheless, electrical conductivity of both compounds decreased due to unintended phase contamination during the synthesis process. The Fe2O3-substituted compounds at the Ni position, in an exact amount of 1 mol, exhibited minimal electrical conductivity. Although the synthesis conditions to produce a single phase of LaFeO3±δ were identified, LaFeO3±δ, despite its low electrical conductivity, is frequently used in electrical devices as a gas detection sensor. The thermal expansion coefficient of all synthesized waste samples is represented in the range of 12–13 × 10−6 °C−1, which is comparable to IT-SOFC electrolyte materials. Furthermore, microstructural investigation revealed that the introduction of Fe into LaNiO3±δ reduced particle size and porosity, ultimately resulting in higher densities. These findings were confirmed through synchrotron radiation x-ray tomographic microscopy (SR-XTM) analysis. The research suggests that converting Fe-waste into a pure phase of Fe2O3 using a strong acid etching technique can serve as a viable precursor for synthesizing conductive materials. This approach enhances the value of industrial waste while also reducing its volume.

Regulating the microstructure and mechanical properties of Al-Cu-Li alloys via optimizing Cu/Li ratio and homogenization

The effect of homogenization process on the microstructure evolution and mechanical properties of Al-Cu-Li alloys with various Cu/Li ratios (ranging from 2.4 to 3.7) are studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and synchrotron radiation X-ray computed tomography (SR-CT) analysis. The results show that with the increase in the Cu/Li ratio, the volume fraction of the secondary phase (fv) in the as-cast alloys gradually increases, and the morphology of the secondary phases transforms from spherical-like to chain-like. For the single-step homogenization (SSH), the fv decreases with increasing homogenization temperature and time. The 510 ℃ /24 h is identified as the optimal SSH regime due to the alloys exhibiting a lower fv and a shorter SSH time than other SSH regimes. Interestingly, the alloys processed by double-step homogenization (DSH) exhibit a lower fv compared with the SSH process. The residual secondary phases consist of a small number of regular block-Al2Cu, dispersed Al20Cu2Mn3 phase and spherical-like Zr-rich phase after SSH and DSH. Furthermore, according to the results of diffusion kinetics analysis, the secondary phases can be dissolved completely into the matrix after homogenization treatment at 510 °C for 22.9 h. Therefore, the 450 ℃ / 12 h+510 ℃ / 24 h (DSH-24) is determined as the optimal homogenization regime. After DSH, a large number of spherical-like GP-Li and Al3Li nanoparticles are precipitated during natural aging. The critical resolved shear stress calculation model suggests that the Al-4.1Cu-1.3Li alloy with a Cu/Li ratio as 3.2 possess high yield strength. The Al-4.1Cu-1.3Li alloy processed by DSH-24 exhibits excellent mechanical properties, with yield strength of 299 MPa, ultimate tensile strength of 449 MPa, and elongation of 18.8 %. This study provides a foundation for the development of high-performance Al-Li alloys.

Metal-organic framework-derived carbon-supported high-entropy alloy nanoparticles applied in ammonia borane hydrolytic dehydrogenation

While high-entropy alloy nanoparticle (HEA NP) catalysts from a sacrificial high-entropy-MOF (HE-MOF) have been attractive, their conventional characterizations may be misleading. Here, we report HEA NPs on HE-MOF-derived carbon (HE-MDC) via direct pyrolysis of MnFeCoNiCu HE-MOF in Ar and H2 at different temperatures and durations with a fast-ramping rate. With the profound investigations of the metal NPs on HE-MDCs by synchrotron radiation X-ray diffraction and absorption, we revealed that the Ar-treated HE-MDCs had either Cu-dominant solid solution or phase-segregated metal NPs, whereas H2 pyrolysis yielded well-dispersed HEA NPs on HE-MDCs. For ammonia borane hydrolysis, although the metal NP size in H2-treated HE-MDC was not the smallest, it showed the fastest dehydrogenation rate (TOF=5.76 molH₂∙min−1∙molcat-1), 2 ∼ 4 times faster than the Ar-treated HE-MDCs. It emphasized the crucial role of elemental uniformity in the HEA NPs over the traditionally reported catalyst size.

An Electrolyte Engineered Homonuclear Copper Complex as Homogeneous Catalyst for Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries suffer from severe polysulfide shuttle, retarded sulfur conversion kinetics and notorious lithium dendrites, which has curtailed the discharge capacity, cycling lifespan and safety. Engineered catalysts act as a feasible strategy to synchronously manipulate the evolution behaviors of sulfur and lithium species. Herein, a chlorine bridge-enabled binuclear copper complex (Cu-2-T) is in situ synthesized in electrolyte as homogeneous catalyst for rationalizing the Li-S redox reactions. The well-designed Cu-2-T provides completely active sites and sufficient contact for homogeneously guiding the Li2S nucleation/decomposition reactions, and stabilizing the lithium working interface according to the synchrotron radiation X-ray 3D nano-computed tomography, small angle neutron scattering and COMSOL results. Moreover, Cu-2-T with the content of 0.25wt% approaching saturated concentration in electrolyte further boosts the homogeneous optimization function in really operated Li-S batteries. Accordingly, the capacity retention of the Li-S battery is elevated from 51.4% to 86.3% at 0.2 C, and reaches 77.0% at 1.0 C over 400 cycles. Furthermore, the sulfur cathode with the assistance of Cu-2-T realizes the stable cycling under the practical scenarios of soft-packaged pouch cell and high sulfur loading (6.5mg cm-2 with the electrolyte usage of 4.5µL mgS -1).

Imaging flow focusing and isolation of aqueous fluids in synthetic quartzite: implications for permeability and retained fluid fraction in deep-seated rocks

The microstructure of realistic fluid–rock systems evolves to minimize the overall interfacial energy, enabling local variations in fluid geometry beyond ideal models. Consequently, the permeability–porosity relationship and fluid distribution in these systems may deviate from theoretical expectations. Here, we aimed to better understand the permeability development and fluid retention in deep-seated rocks at low fluid fractions by using a combined approach of high-resolution synchrotron radiation X-ray computed microtomography imaging of synthesized rocks and numerical permeability computation. We first synthesized quartzite using a piston-cylinder apparatus at different fluid fractions and wetting properties (wetting and non-wetting systems with dihedral angles of 52° and 61°–71°, respectively) under conditions of efficient grain growth. Although all fluids should be connected along grain edges and tubules in the homogeneous isotropic wetting fluid–rock system enabling segregation by gravitational compaction in natural settings, the fluid connectivity rapidly decreased to ~ 0 when the total fluid fraction decreased to 0.030–0.037, as the non-ideality of quartzite, including the interfacial energy anisotropy (i.e., grain faceting), became critical. In non-wetting systems, where the minimum energy fluid fraction based solely on the dihedral angle is ~ 0.015–0.035, the isolated (disconnected) fractions was 0.048–0.062. A streamline computation in the non-wetting system revealed that with decreasing total porosity, flow focusing into fewer channels maintained permeability, allowing the effective segregation of the connected fluids. These results provide insight into how non-wetting fluids segregate from rocks and exemplify the fraction of retained fluids in non-wetting systems. Thus, the findings suggest a potential way for wetting system fluids to be transported into the deep Earth's interior, and the amount of fluids dragged down to the Earth’s interior could be higher than what was previously estimated.

Appraising protein conformational changes by resampling time-resolved serial x-ray crystallography data.

With the development of serial crystallography at both x-ray free electron laser and synchrotron radiation sources, time-resolved x-ray crystallography is increasingly being applied to study conformational changes in macromolecules. A successful time-resolved serial crystallography study requires the growth of microcrystals, a mechanism for synchronized and homogeneous excitation of the reaction of interest within microcrystals, and tools for structural interpretation. Here, we utilize time-resolved serial femtosecond crystallography data collected from microcrystals of bacteriorhodopsin to compare results from partial occupancy structural refinement and refinement against extrapolated data. We illustrate the domain wherein the amplitude of refined conformational changes is inversely proportional to the activated state occupancy. We illustrate how resampling strategies allow coordinate uncertainty to be estimated and demonstrate that these two approaches to structural refinement agree within coordinate errors. We illustrate how singular value decomposition of a set of difference Fourier electron density maps calculated from resampled data can minimize phase bias in these maps, and we quantify residual densities for transient water molecules by analyzing difference Fourier and Polder omit maps from resampled data. We suggest that these tools may assist others in judging the confidence with which observed electron density differences may be interpreted as functionally important conformational changes.

Relationship between the nanometer-scale structures of amylopectin molecules and temperature dependence of internal structures of starch granules in endosperm of starch branching enzyme 2b (be2b) allelic mutant lines from japonica rice

We analyzed the relationship between the nanometer-scale structure of amylopectin and physicochemical properties such as thermal properties of starch granules and higher-order internal structure of starch granules evaluated by using synchrotron radiation X-ray scattering and scanning electron microscopy. In this study, a line of allelic mutants of rice lacking in starch branching enzyme IIb (BEIIb) activity in their endosperm were used as starch sources. The crystal lattice changed from A-type to C- and B-type. The nanoscale cluster size, and higher-order structures of the starch granules varied among mutant lines. The thermal gelatinization properties of the rice-derived starch samples, as well as the dependence of this process on their crystal structure, were evaluated using differential scanning calorimetry and synchrotron X-ray scattering. After gelatinization, several nm-scaled density fluctuations owing to the formation of gel balls were observed. These fluctuations of all starch samples correlated with the cluster size decreased with the temperature.

A new Antarctic species of Orchomenella G.O. Sars, 1890 (Amphipoda: Lysianassoidea: Tryphosidae): is phase-contrast micro-tomography a mature technique for digital holotypes?

Abstract The purpose of this paper is to describe a new species of Antarctic amphipod of the genus Orchomenella Sars, 1890, Orchomenella rinamontiae sp. nov., and to investigate whether high-resolution images of the surface anatomy obtained ‘in situ’ with synchrotron radiation X-ray phase-contrast micro-tomography (SR-PhC micro-CT) can replace classical approaches to describe a new species. The phylogenetic analyses based on the gene COI support the morphologically based taxonomic assignment. The SR-PhC micro-CT was useful for viewing the three-dimensional reconstructions, with the great advantages that the specimen could be rotated around all axes and that it was possible digitally to remove sections of the image that might have obscured areas of the amphipod on which we were focusing. However, it is not yet a completely reliable technique to describe a new species fully. Classical descriptions using light microscopy and scanning electron microscopy are still necessary. Nevertheless, SR-PhC micro-CT is a promising technique that has the potential to revolutionize the way we study biological samples, accelerating the study of biodiversity.

Mechanical, Thermal Properties, and Extreme Phase Stability of High-Entropy Diborides (V0.2Nb0.2Ta0.2Cr0.2W0.2)B2.

High-entropy diborides (HEDBs) have gained significant attention in industrial applications due to their vast composition space and tunable properties. We propose a solid solution reaction at high temperatures and pressures that successfully synthesized and sintered a novel, dense, and phase-pure HEDB (V0.2Nb0.2Ta0.2Cr0.2W0.2)B2. A high asymptotic Vickers hardness of 26.3 ± 0.6 GPa and a bulk modulus of 320.5 ± 10.6 GPa were obtained. Additionally, we investigated the thermal oxidation process using TG-DSC from room temperature to 1500 °C and explored the phase stability of HEDBs under high-pressure conditions through in situ high-pressure synchrotron radiation X-ray diffraction. We analyzed the formation of lattice distortion, chemical bonding, and band structure in (V0.2Nb0.2Ta0.2Cr0.2W0.2)B2 using first-principles calculations. Surprisingly, we found that the predominant distortion in diborides occurs in the boron layer, supported by ELF. This may be due to uneven electron transfer rather than a straightforward correlation with the atomic radius. These results provide a novel synthesis process and additional experimental data on the mechanical and thermal properties and high-pressure phase stability of HEDBs. Our study offers further insights into the microscopic structure of lattice distortion in HEDBs, which could prove crucial for the selection and design of engineering advanced HEDBs.

Spatial control of perilacunar canalicular remodeling during lactation

Osteocytes locally remodel their surrounding tissue through perilacunar canalicular remodeling (PLR). During lactation, osteocytes remove minerals to satisfy the metabolic demand, resulting in increased lacunar volume, quantifiable with synchrotron X-ray radiation micro-tomography (SRµCT). Although the effects of lactation on PLR are well-studied, it remains unclear whether PLR occurs uniformly throughout the bone and what mechanisms prevent PLR from undermining bone quality. We used SRµCT imaging to conduct an in-depth spatial analysis of the impact of lactation and osteocyte-intrinsic MMP13 deletion on PLR in murine bone. We found larger lacunae undergoing PLR are located near canals in the mid-cortex or endosteum. We show lactation-induced hypomineralization occurs 14 µm away from lacunar edges, past a hypermineralized barrier. Our findings reveal that osteocyte-intrinsic MMP13 is crucial for lactation-induced PLR near lacunae in the mid-cortex but not for whole-bone resorption. This research highlights the spatial control of PLR on mineral distribution during lactation.

In situ 3D crystallographic characterization of deformation-induced martensitic transformation in a metastable Fe–Cr–Ni austenitic alloy by X-ray microtomography

Excellent strength–ductility balance in metastable Fe–Cr–Ni austenitic alloys stems from phase transformation from austenite (fcc structure) to αʹ martensite (bcc structure) during deformation, namely deformation-induced αʹ martensitic transformation (DIMT). Here, DIMT in a metastable Fe–17Cr–7Ni austenitic alloy was detected in situ and characterized in three dimensions (3D) by employing synchrotron radiation X-ray microtomography. This technique utilizes refraction contrast, which is attributable to the presence of phase boundaries between the parent austenite and the newly formed αʹ martensite phase. By combining microtomography and position-sensitive X-ray diffraction, we succeeded in crystallographically identifying multiple αʹ martensite phases continuously transformed in four groups from a single parent austenitic phase.

A Non-destructive Evaluation of Microstructural Analysis in Sn-Ag-Cu Solder Joint by Synchrotron X-Ray Radiation Tomography

This paper demonstrates a non-destructive technique to evaluate the internal microstructure in the Sn-Ag-Cu (SAC) solder joint through synchrotron X-ray radiation tomography. Synchrotron X-ray tomography is increasingly utilized for characterizing the internal microstructure of materials in 3D images. A 3D model is reconstructed from a set of 2D projection images taken from different angles and angular position during the sample rotation, thus it could provide a more comprehensive description of the microstructure of an alloy compared to 2D images. In this paper, it is successfully observed and evaluated the internal microstructure of a 900 μm solder joint sample. The key principles and methods of synchrotron X-ray tomography are briefly described. Examples of quantitative and qualitative assessments on the grain refinement effect of Mg addition to SAC35 solder joint are also presented in this paper.

In-situ observation of solidification behaviors of Fe-Mn-Cr-Ni-Si alloy during TIG melt-run welding using synchrotron radiation X-ray

The solidification behaviors, including the solidification cracking and solidification mode of the Fe-Mn-Cr-Ni-Si alloys at the weld bead during tungsten inert gas (TIG) melt-run welding, were examined by time-resolved in-situ observations using synchrotron radiation X-ray imaging and X-ray diffraction. The dynamics of initiation and propagation of solidification cracking at the weld bead could be observed at the dendrite scale. For the specimen solidified in the austenite mode at a welding speed of 10 mm/s, solidification cracking with a zigzag interface developed via the coalescence of many small pores at the centerline, where the columnar dendrite tips impinged. Quantitative image analysis indicated that the local tensile strain was highly localized at the centerline, and the critical local tensile strain for the initiation of solidification cracking was approximately 0.04. For the specimen solidifying in the ferrite-austenite mode at the welding speed of 10 mm/s, the centerline solidification cracking was suppressed by the formation of many equiaxed γ-Fe dendrites ahead of the growing columnar δ-Fe dendrites. Grain refinement at the centerline can be achieved at a welding speed of more than 7 mm/s without requiring inoculants.

Combinatorial processing and evaluation of the phase evolution and oxidation behavior of Hf-Al-Si refractory complex concentrated alloys

Refractory complex concentrated alloys (RCCAs) are a unique group of materials defined by the shared principality between all alloying elements and the tailorable properties at high temperatures (>1000 °C). RCCA systems can be optimized using high-throughput processing which allows for simultaneous characterization and testing over a range of compositions. A compositionally-graded Hf-Al-Si coating was compositionally mapped using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) to identify relative compositions as a function of position on the wafer. High temperature CALPHAD phase diagrams and thermodynamic predictions for a Hf50Al50-xSix alloy and its (Hf50Al50-xSix)1-yOy oxide were coupled with experimental results. The RCCA wafer was heat treated at 1200 °C to observe any phase changes and oxidation behavior at elevated temperatures. Characterization of the RCCA was performed before and after heating using synchrotron radiation X-ray diffraction (SR-XRD) to identify the phases and oxidation states as a function of the compositional gradient and to determine an alloy composition range with the least oxidation. SR-XRD pre- and post-treating revealed an inherent amorphous Hf20Al7Si13 phase across the as-deposited coating, similarities in spectra pre- and post-treating for compositions containing less Hf and more Al and Si relative to the entire gradient film, and the presence of significant HfO2 and Al6Si2O13 oxide for compositions consisting of more Hf and less Al and Si relative to the entire gradient film. The SR-XRD and CALPHAD modeling suggests that compositions of 31–48 at.% Hf, 21–48 at.% Al, and 9–27 at.% Si display the greatest resistance to detrimental oxidation upon heating to 1200 ∘C.

Dissecting of Atomic Morphology of Superfine Pulverized Coal Based on X-ray Pair Distribution Function

Resolving the atomic structure information of the aromatic layers in coal plays a crucial role in understanding the generation mechanisms of NOx during coal combustion and further reducing the formation of NOx from the source. This study reveals the distribution of X-ray diffraction bands of superfine pulverized coal using a high-resolution synchrotron radiation X-ray Diffraction (HRXRD) facility, discussing the distribution of atomic distances and atomic density in aromatic layers through pair distribution function (PDF) methods. Furthermore, the influences of mechanochemistry on the evolution of atomic morphology are focused on. The results show that the PDF of coal gradually stabilizes when r &amp;gt; 8 Å, showing the short-range order of graphite-like structure. Additionally, due to the limitations of scanning angle and X-ray energy, atomic distances in aromatic layers for coal are significantly greater than that of pure graphene. Enhanced mechanochemical effects make the peaks 1, 2, and 3 of coal PDF more similar to graphene&amp;apos;s by condensing alkyl side chains into smaller, regular aromatic layers when the particle size decreases. With the enhancement of mechanochemical effects, coals with different metamorphic degrees exhibit different aromatic evolution patterns. The aromaticity of NMG coal first decreases and then increases, while the aromaticity of YQ coal shows the opposite trend. The results can provide deeper insights into the atomic structure of coal macromolecular, which can facilitate the advancement of novel ultra-low NOx combustion methods and support the construction of precise coal macromolecular models.

Retrogradation inhibition and intragranular distribution in cooked rice by addition of α-glucosidase (AG) and branching enzyme (BE)

The effect of inhibiting retrogradation and changes in chain length distribution by AG and BE, which are texture-modifying enzymes, has been clarified. To ascertain in which part of the rice grain retrogradation occurs and which enzymes is most effective, the degree of retrogradation in each part of the rice grain was measured from the surface to the core of the same rice grain using a synchrotron radiation X-ray beam with a beam size of 100 μm. Retrogradation was effectively suppressed at all measurement sites by enzyme addition, although the effect of enzymes was greater at the surface. Rice grain sections were stained with iodine and eosin. A starch layer that does not easily form a complex with iodine was observed inside the protein layer at the surface of cooked rice. A starch layer with a long molecular chain that forms complexes with iodine was observed inside the rice grain.

In-situ Synchrotron Radiation XRD Crystal Structure and Microstructure Analysis of CaO-ZrO2 solid-solution at 1100°C with Prolonged Heating

Abstract The structural analysis of the CaO-ZrO2 solid-solutions was carried out using in-situ synchrotron radiation X-ray diffraction (SR-XRD). CaO-ZrO2 solid-solutions with 0, 2.5, and 5 at.% CaO contents were synthesized via a solid-solid ball milling technique. The amorphous ZrO2 powder was synthesized via co-precipitation using ZrCl4 and NH4OH as precursors, while the CaO powder was purified from a local limestone. In-situ SR-XRD measurements were conducted on the CaO-ZrO2 mixtures by independently heating them to 1100°C for different holding times of 0, 12, 24, and 36 minutes using a DHS furnace. Qualitative analysis of all SR-XRD patterns showed that only tetragonal zirconia (t-ZrO2) was present. The crystallite size of tetragonal zirconia ranged from 17 to 22 nm, depending on calcination holding time and CaO addition. Further analysis showed that the tetragonality (c/a) parameter remained relatively constant over the 36-minute holding time. However, the introduction of CaO led to an insignificant reduction in tetragonality, averaging 0.292%.

Structure-performance relationship of polypropylene/elastomer/carbon black composites as high voltage cable shielding layer

As polypropylene (PP) is a competitive insulating material for next generation high-voltage cable, the corresponding PP based cable semi-conductive shielding layer material needs to be developed. This paper developed an excellent material prescription and proposed an analytical method of structure-performance relationship for the application and the evaluation of PP-based cable shielding layer. First, PP/POE/CB and PP/SEBS/CB composites with different carbon black (CB) loading were prepared and their electrical and mechanical properties were compared. Through thermal analysis technique, crystalline property and thermal stability of the composites were studied in detail. And the synchrotron radiation X-ray scattering techniques were employed to analyze the distribution of carbon black in the blend semi-quantitatively. The analysis result turns out the enrichment of carbon black in POE phase and its instability at high temperature limits its application under cable operation conditions. In contrast, PP/SEBS/CB30phr is recommended for lower thermal deformation, lower PTC effect and better mechanical parameters.

Chemometric Speciation of Trace Elements in Indonesian Coal Imported by Indian Thermal Power Stations - A Comparative Study with Indian Coals using SRXRF

ABSTRACT Imported Indonesian coal samples collected from thermal power plants were analyzed using Synchrotron Radiation X-ray Fluorescence (SRXRF). Sixteen inorganic elements As, Ca, Cr, Co, Cu, Fe, K, Mn, Ni, Pb, Rb, Se, Sr, Ti, V, and Zn were quantified. To ascertain the abundance in the analyzed samples compared to Clarke values for world coals, the enrichment factor for each element was measured. The analytical results were interpreted using chemometric techniques, namely Pearson’s correlation analysis, hierarchical cluster analysis, and principal component analysis. This study revealed three principal components contributing to 87.99% of the total variance in the data.