Millimeter-Size All-inorganic Perovskite Crystalline Thin Film Grown by Chemical Vapor Deposition
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Zhou, Yuan↗
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Decoupling first-cycle capacity loss mechanisms in sulfide solid-state batteries
Solid-state batteries (SSBs) promise more energy-dense storage than liquid electrolyte lithium-ion batteries (LIBs). However, first-cycle capacity loss is higher in SSBs than in LIBs due to interfacial reactions. The chemical evolution of key interfaces in SSBs has been extensively characterized. Electrochemically, however, we lack a versatile strategy for quantifying the reversibility of solid electrolyte (SE) redox for established and next-generation SSB electrolytes. In this work, we perform tailored electrochemical tests and operando X-ray diffraction to disentangle reversible and irreversible sources of capacity loss in positive electrodes composed of Li 6 PS 5 Cl SE, Li(Ni 0.5 Mn 0.3 Co 0.2 )O 2 (NMC), and carbon conductive additives. We leverage an atypically low voltage cutoff (2.0 V vs. Li/Li + ) to quantify the reversibility of SE redox. Using slow (5.5 mA g NMC −1 ) cycling paired with >100 h low-voltage holds, our cells achieve a surprising 96.2% first-cycle coulombic efficiency, which is higher than previously reported (mean: 72%, maximum: 91.6% across surveyed literature). We clarify that sluggish NMC relithiation kinetics have been historically mistaken for permanently irreversible capacity loss. In conclusion, through systematic decoupling of loss mechanisms, we uncover the unexpected reversibility of SE redox and isolate the major contributors to capacity loss, outlining a strategy for accurate assessment of next-generation SE materials and interface modifications.
54 ENVIRONMENTAL SCIENCES↗
Ultrafast radiographic imaging and tracking: An overview of instruments, methods, data, and applications
Ultrafast radiographic imaging and tracking (U-RadIT) use state-of-the-art ionizing particle and light sources to experimentally study sub-nanosecond transients or dynamic processes in physics, chemistry, biology, geology, materials science and other fields. These processes are fundamental to modern technologies and applications, such as nuclear fusion energy, advanced manufacturing, communication, and green transportation, which often involve one mole or more atoms and elementary particles, and thus are challenging to compute by using the first principles of quantum physics or other forward models. One of the central problems in U-RadIT is to optimize information yield through, e.g. high-luminosity X-ray and particle sources, efficient imaging and tracking detectors, novel methods to collect data, and large-bandwidth online and offline data processing, regulated by the underlying physics, statistics, and computing power. We review and highlight recent progress in: (a.) Detectors such as high-speed complementary metal-oxide semiconductor (CMOS) cameras, hybrid pixelated array detectors integrated with Timepix4 and other application-specific integrated circuits (ASICs), and digital photon detectors; (b.) U-RadIT modalities such as dynamic phase contrast imaging, dynamic diffractive imaging, and four-dimensional (4D) particle tracking; (c.) U-RadIT data and algorithms such as neural networks and machine learning, and (d.) Applications in ultrafast dynamic material science using XFELs, synchrotrons and laser-driven sources. Hardware-centric approaches to U-RadIT optimization are constrained by detector material properties, low signal-to-noise ratio, high cost and long development cycles of critical hardware components such as ASICs. Interpretation of experimental data, including comparisons with forward models, is frequently hindered by sparse measurements, model and measurement uncertainties, and noise. Alternatively, U-RadIT make increasing use of data science and machine learning algorithms, including experimental implementations of compressed sensing. Machine learning and artificial intelligence approaches, refined by physics and materials information, may also contribute significantly to data interpretation, uncertainty quantification and U-RadIT optimization.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Novel Perovskite Semiconductors for the Detection of Special Nuclear Material
Special nuclear material detection using portable, highly efficient detectors is of paramount importance to national security and environmental monitoring. Current neutron detectors, including gas proportional counters and scintillators, are not suitable for discrete or portable monitoring due to size, weight, and power limitations. For example, 3 He gas proportional detectors have significant drawbacks, including long absorption lengths, high voltage requirements, and dependence on the availability of 3 He. The goal of this project is to synthesize a novel, boron-based perovskite semiconductor crystals to create a more efficient and more portable neutron detector. This innovative material will lead to a significant decrease in power and size requirements with higher operating temperatures than other traditional solid-state detectors. Directly incorporating 10 B eliminates the need for a conversion layer and leads to high neutron absorption coefficients. In this seedling project, we used inverse temperature crystallization with boron precursors to create CH 3 NH 3 PbI 3-x (BF 4 ) x . The crystals were analyzed with X-ray diffraction, but the results were inconclusive. Future work will focus on tailoring the solution growth and selecting appropriate solvents and precursors.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
End-to-end deep learning pipeline for real-time Bragg peak segmentation: from training to large-scale deployment
X-ray crystallography reconstruction, which transforms discrete X-ray diffraction patterns into three-dimensional molecular structures, relies critically on accurate Bragg peak finding for structure determination. As X-ray free electron laser (XFEL) facilities advance toward MHz data rates (1 million images per second), traditional peak finding algorithms that require manual parameter tuning or exhaustive grid searches across multiple experiments become increasingly impractical. While deep learning approaches offer promising solutions, their deployment in high-throughput environments presents significant challenges in automated dataset labeling, model scalability, edge deployment efficiency, and distributed inference capabilities. We present an end-to-end deep learning pipeline with three key components: (1) a data engine that combines traditional algorithms with our peak matching algorithm to generate high-quality training data at scale, (2) a modular architecture that scales from a few million to hundreds of million parameters, enabling us to train large expert-level models offline while deploying smaller, distilled models at the edge, and (3) a decoupled producer-consumer architecture that separates specialized data source layer from model inference, enabling flexible deployment across diverse computing environments. Using this integrated approach, our pipeline achieves accuracy comparable to traditional methods tuned by human experts while eliminating the need for experiment-specific parameter tuning. Although current throughput requires optimization for MHz facilities, our system's scalable architecture and demonstrated model compression capabilities provide a foundation for future high-throughput XFEL deployments.
Wang, Cong↗
Overcoming Fundamental Limitations in Adsorbent Design: Alkene Adsorption by Non-porous Copper(I) Complexes
Purifying alkenes from alkanes requires cryogenic distillation. This consumes energy equivalent to countries of ca. 5 million people. Replacing distillation with adsorption processes would significantly increase energy efficiency. Trade-offs between kinetics, selectivity, capacity, and heat of adsorption have prevented production of an optimal adsorbent. Here, we report adsorbents that overcome these trade-offs. [Cu-Br] 3 and [Cu-H] 3 are air-stable trinuclear complexes that undergo reversible solid-state inter-molecular rearrangements to produce dinuclear [Cu-Br∙(alkene)] 2 and [Cu-H∙(alkene)] 2 . The reversible solid-state rearrangement, confirmed in situ using powder X-ray diffraction, allows adsorbent design trade-offs to be overcome, coupling low heat of adsorption (-10 to -17 kJ mol -1 alkene ), high alkene:alkane selectivity (47; 29), and uptake capacity (>2.5 molalkene mol -1 Cu3 ). Most remarkably, [Cu-H] 3 displays fast uptake and regenerates capacity within 10 minutes.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Direct Observation of Ammonia Storage in UiO-66 Incorporating Cu(II) Binding Sites
The presence of active sites in metal–organic framework (MOF) materials can control and affect their performance significantly in adsorption and catalysis. However, revealing the interactions between the substrate and active sites in MOFs at atomic precision remains a challenging task. Here, we report the direct observation of binding of NH 3 in a series of UiO-66 materials containing atomically dispersed defects and open Cu(I) and Cu(II) sites. While all MOFs in this series exhibit similar surface areas (1111–1135 m 2 g –1 ), decoration of the -OH site in UiO-66-defect with Cu(II) results in a 43% enhancement of the isothermal uptake of NH 3 at 273 K and 1.0 bar from 11.8 in UiO-66-defect to 16.9 mmol g –1 in UiO-66-Cu II . A 100% enhancement of dynamic adsorption of NH 3 at a concentration level of 630 ppm from 2.07 mmol g –1 in UiO-66-defect to 4.15 mmol g –1 in UiO-66-Cu II at 298 K is observed. In situ neutron powder diffraction, inelastic neutron scattering, and electron paramagnetic resonance, solid-state nuclear magnetic resonance, and infrared spectroscopies, coupled with modeling reveal that the enhanced NH 3 uptake in UiO-66-Cu II originates from a {Cu(II)···NH 3 } interaction, with a reversible change in geometry at Cu(II) from near-linear to trigonal coordination. This work represents the first example of structural elucidation of NH 3 binding in MOFs containing open metal sites and will inform the design of new efficient MOF sorbents by targeted control of active sites for NH 3 capture and storage.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Ionization-Based Optical Structures for the Control of Short-Pulse Lasers (Abbreviated LDRD Report)
The intensity of light from the highest-power lasers is limited by the size of the optics required to amplify, compress, transport, and focus a laser beam. Indeed, optics damage puts strict constraints on the laser energy density that solid optics can sustain; this leads to enormous optics sizes and limits the maximum intensity that these lasers can achieve. In this project we investigated new types of diffractive optics based on mixtures of neutral gas and plasmas. The basic idea is to interfere laser beams in a gas near the ionization threshold, so that plasma is created in the constructive interference regions (i.e., the “bright” fringes of the interference pattern) while the destructive interference regions remain a neutral gas. The resulting refractive index modulation, due to the different indices in gas vs. plasma, effectively turns such structures into diffractive optics elements. We proposed several new types of optics based on this general concept: i) reflection gratings, which can act as mirrors of “pulse cleaners” to eliminate laser pre-pulse; ii) transmission gratings, as part of a new type of pulse compression scheme with the potential to achieve laser intensities orders of magnitude above what is currently feasible using solid-state optics; and iii) holographic lenses, to focus high-power lasers. We conducted laboratory experiments which demonstrated high efficiency reflection gratings, paving the way for practical applications of our new concepts.
47 OTHER INSTRUMENTATION↗
Mechanocatalytic Ammonia Synthesis over TiN in Transient Microenvironments
Environmentally friendly and energy-efficient ways to produce ammonia are essential to meet global food demands. In this study, a new approach for ammonia production at nominally ambient conditions is introduced. As proof of concept, ammonia is synthesized mechanocatalytically by ball milling titanium in a continuous gas flow. The ammonia synthesis reaction is proposed to follow a transient Mars–van Krevelen mechanism under mechanically activated conditions, where molecular nitrogen incorporation into the titanium lattice and titanium nitride hydrogenation occur in thermodynamically distinct environments. X-ray powder diffraction and X-ray absorption spectroscopy confirm the formation of titanium nitride from titanium and N2. The reactivity of nitrided titanium supports that lattice nitrogen plays a role in ammonia formation. The in situ formed titanium nitride is catalytically active, and the nitride regeneration reaction is determined to be the rate-limiting step. A preliminary technoeconomic analysis shows that this approach could be feasible for distributed ammonia production.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Unlocking High Capacity and Reversible Alkaline Iron Redox Using Silicate-Sodium Hydroxide Hybrid Electrolytes
Alkaline iron (Fe) batteries are attractive due to the high abundance, low cost, and multiple valent states of Fe but show limited columbic efficiency and storage capacity when forming electrochemically inert Fe 3 O 4 on discharging and parasitic H 2 on charging. Herein, sodium silicate is found to promote Fe(OH) 2 /FeOOH against Fe(OH) 2 /Fe 3 O 4 conversions. Electrochemical experiments, operando X-ray characterization, and atomistic simulations reveal that improved Fe(OH) 2 /FeOOH conversion originates from (i) strong interaction between sodium silicate and iron oxide and (ii) silicate-induced strengthening of hydrogen-bond networks in electrolytes that inhibits water transport. Furthermore, the silicate additive suppresses hydrogen evolution by impairing energetics of water dissociation and hydroxyl de-sorption on iron surfaces. In conclusion, this new silicate-assisted redox chemistry mitigates H 2 and Fe 3 O 4 formation, improving storage capacity (199 mAh g -1 in half-cells) and coulombic efficiency (94 % after 400 full-cell cycles), paving a path to realizing green battery systems built from earth-abundant materials.
36 MATERIALS SCIENCE↗
Inversion of dynamical Bragg intensities to complex structure factors by iterated projections. For Ultramic. 2020. ("Pico" Festschrift, May 2021)
We discuss a method for recovering complex structure factors from many simultaneously excited Bragg beam intensities is described. The method is applied to simulated transmission electron diffraction data over a wide range of crystal thickness and beam energies. The method is based on iterated projections between structure and scattering matrices, which are related by a matrix unitary transformation, exponential, which we invert. The algorithm removes multiple-scattering perturbations from diffraction data and might be extended to other fields, including X-ray and neutron diffraction and cryo-electron microscopy. Because coherent multiple scattering involves interference between Bragg beams, the method also solves the phase problem. Unlike dynamical inversion from electron microscope images or ptychography data, the method, which starts with Bragg beam intensities, provides complex structure factors unaffected by focusing errors or resolution limitations imposed by lenses. We provide inversions from simulated data with 441 simultaneously excited Bragg beams over a range of thickness and beam energy. We discuss the retrieval of chirality information from enantiomorphs, the efficient incorporation of symmetry information using the irreducible representation of the group of structure matrices, and the effect of HOLZ lines to provide three-dimensional information.
97 MATHEMATICS AND COMPUTING↗
Multivariate Flexible Framework with High Usable Hydrogen Capacity in a Reduced Pressure Swing Process
Step-shaped adsorption-desorption of gaseous payloads by flexible metal-organic frameworks can facilitate the delivery of large usable capacities with significantly reduced energetic penalties. This is desirable for the storage, transport, and delivery of H 2 , as prototypical adsorbents require large swings in pressure and temperature to achieve usable capacities approaching their total capacities. However, the weak physisorption of H 2 typically necessitates undesirably high pressures to induce the framework phase change. As de novo design of flexible frameworks is exceedingly challenging, the ability to intuitively adapt known frameworks is required. We demonstrate that the multivariate linker approach is a powerful tool for tuning the phase change behavior of flexible frameworks. In this work, 2-methyl-5,6-difluorobenzimidazolate was solvothermally incorporated into the known framework CdIF-13 (sod-Cd(benzimidazolate) 2 ), resulting in the multivariate framework sod-Cd(benzimidazolate) 1.87 (2-methyl-5,6-difluorobenzimidazolate) 0.13 (ratio = 14:1), which exhibited a considerably reduced stepped adsorption threshold pressure while maintaining the desirable adsorption-desorption profile and capacity of CdIF-13. At 77 K, the multivariate framework exhibits stepped H 2 adsorption with saturation below 50 bar and minimal desorption hysteresis at 5 bar. At 87 K, saturation of step-shaped adsorption occurs by 90 bar, with hysteresis closing at 30 bar. These adsorption-desorption profiles enable usable capacities in a mild pressure swing process above 1 mass %, representing 85-92% of the total capacities. Here this work demonstrates that the desirable performance of flexible frameworks can be readily adapted through the multivariate approach to enable efficient storage and delivery of weakly physisorbing species.
08 HYDROGEN↗
Influence of dislocations and twin walls in BaTiO 3 on the voltage-controlled switching of perpendicular magnetization
In this work, we investigate the influence of dislocations and twin walls in BaTiO 3 on its ferroelectric response and the resulting effect on the perpendicular magnetic anisotropy (PMA) of a strain-coupled [Co\Ni] n film. A dense twinned structure in conjunction with a high dislocation density significantly reduces the converse piezoelectric effect of BaTiO 3 by hindering the propagation of newly nucleated domains with an applied electric field. This, in turn, results in a modest reduction of the PMA of the ferromagnetic layer. On the other hand, the ferroelectric polarization reorients from [100] to [001] direction in a dislocation-free BaTiO 3 , inducing the maximum achievable in-plane compressive strain of 1.1%. A large fraction of this uniaxial strain is transferred to the magnetoelastically coupled ferromagnetic layers whose magnetization switches to in plane via the inverse magnetostriction effect. This work reveals the critical role of the interplay between twin walls and dislocations within a ferroelectric substrate in the performance of multiferroic heterostructures and provides insight into the development of highly energy-efficient magnetoelectric devices.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Thermodynamically Driven Synthetic Optimization for Cation-Disordered Rock Salt Cathodes
Relating the synthesis conditions of materials to their functional performance has long been an experience-based trial-and-error process. However, this methodology is not always efficient in identifying an appropriate protocol and can lead to overlooked opportunities for the performance optimization of materials through simple modifications of the synthesis process. In this work, we systematically track the structural evolution in the synthesis of a representative disordered rocksalt (a promising next-generation Li-ion cathode material) at the scale of both the long-range crystal structure and the short-range atomic structure using various in situ and ex situ techniques, including transmission electron microscopy, X-ray diffraction, and pair distribution function analysis. Further, an optimization strategy is proposed for the synthesis protocol, leading to a remarkably enhanced capacity (specific energy) of 313 mAh g –1 (987 Wh kg –1 ) at a low rate (20 mA g –1 ), with a capacity of more than 140 mAh g –1 retained even at a very high cycling rate of 2,000 mA g –1 . This strategy is further rationalized using ab initio calculations, and important opportunities for synthetic optimization demonstrated in this study are highlighted.
36 MATERIALS SCIENCE↗
Why Perovskite Thermal Stress is Unaffected by Thin Contact Layers
Metal halide perovskite photovoltaics have emerged as a high efficiency, low-cost alternative that can potentially rival or enhance conventional silicon technology. Despite exceptional initial power conversion efficiencies, achieving compliance with international standards and widespread adoption requires further enhancements to their operational stability. Notably, addressing mechanical strain and stress in brittle perovskites has emerged as a pivotal approach to mitigate chemical degradation and improve reliability during thermal cycling. Here, in this study, a popularized strain engineering strategy is investigated in which a high coefficient of thermal expansion (CTE) hole transport layer (i.e., PDCBT) is cast onto inorganic perovskite (CsPbI 2 Br) at 100 °C. Contrary to previously published results, the X-ray diffraction (XRD):Sin 2 ψ and substrate curvature measurement techniques show that the hole transport layer has no discernible impact on perovskite strain. The accuracy of the XRD:Sin 2 ψ method for measuring strain is highlighted in contrast to an analysis based on shifts of single XRD peaks which can be influenced by multiple artifacts. The findings in this study are in accordance with mechanics theory: thin layers are unable to induce significant strain changes in perovskite thin films as the force they apply is negligible compared to that applied by a thick and stiff substrate.
14 SOLAR ENERGY↗
A Novel Experimental Approach to Understand the Transport of Nanodrugs
Nanoparticle-based drugs offer attractive advantages like targeted delivery to the diseased site and size and shape-controlled properties. Therefore, understanding the particulate flow of the nanodrugs is important for effective delivery, accurate prediction of required dosage, and developing efficient drug delivery platforms for nanodrugs. In this study, the transport of nanodrugs including flow velocity and deposition is investigated using three model metal oxide nanodrugs of different sizes including iron oxide, zinc oxide, and combined Cu-Zn-Fe oxide synthesized via a modified polyol approach. The hydrodynamic size, size, morphology, chemical composition, crystal phase, and surface functional groups of the water-soluble nanodrugs were characterized via dynamic light scattering, transmission electron microscopy, scanning electron microscopy-energy dispersive X-ray, X-ray diffraction, and fourier transform infrared spectroscopy, respectively. Two different biomimetic flow channels with customized surfaces are developed via 3D printing to experimentally monitor the velocity and deposition of the different nanodrugs. A diffusion dominated mechanism of flow is seen in size ranges 92 nm to 110 nm of the nanodrugs, from the experimental velocity and mass loss profiles. The flow velocity analysis also shows that the transport of nanodrugs is controlled by sedimentation processes in the larger size ranges of 110–302 nm. However, the combined overview from experimental mass loss and velocity trends indicates presence of both diffusive and sedimentation forces in the 110–302 nm size ranges. It is also discovered that the nanodrugs with higher positive surface charges are transported faster through the two test channels, which also leads to lower deposition of these nanodrugs on the walls of the flow channels. The results from this study will be valuable in realizing reliable and cost-effective in vitro experimental approaches that can support in vivo methods to predict the flow of new nanodrugs.
36 MATERIALS SCIENCE↗
Zero Valent Iron for Reductive Removal of Technetium-99 from Aqueous Sulfate Solutions - 20347
This research investigates the reductive removal of technetium-99 ({sup 99}Tc) by zero valent iron (ZVI) from low activity waste (LAW) off-gas condensate simulant as a secondary treatment after recovery from vitrification planned at the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Due to its high volatility, only a fraction of Tc{sup (VII)} will be incorporated into glass waste forms. Volatilized Tc will be captured by an off-gas treatment system with current plans to recycle off-gas condensate back to the vitrification facility. The scheme with off-gas recycling will increase Tc loading in the glass waste, but will also increase the concentrations of sulfate, halides, and other problematic constituents impeding overall LAW processing and increasing volume of the glass product. This study focuses on Tc{sup (VII)} removal by ZVI as a feasible pathway to minimize off-gas condensate recycling, which may result in a reduction in the volumes of LAW waste to be immobilized and subsequent cost savings. ZVI is an established treatment agent for redox-active contaminants such as trichloroethylene, nitrate, arsenic, chromium, phenol, and others. It is a commercially available and cost-effective material. Our previous experiments showed that ZVI is very efficient for the reductive removal of {sup 99}Tc. In this work we studied ZVI oxidation under aerobic conditions at pH 7 with 0.1 M Na{sub 2}SO{sub 4} solution (ionic strength, IS, 0.3 M) in the presence and absence of {sup 99}Tc. The concentration of {sup 99}Tc and the changes in pH, dissolved oxygen (DO), and oxidation-reduction potential (ORP) of the simulated solutions were monitored over 8 days. The formation of iron oxide phases was probed by X-ray diffraction (XRD). Obtained results suggest that ZVI contact time with {sup 99}Tc containing solutions for 6 hours resulted in nearly complete removal of {sup 99}Tc from the aqueous phase. XRD analysis showed that the oxidation of ZVI is rapid with formation of magnetite (Fe{sub 3}O{sub 4}) with minor percentage of goethite and maghemite. This work is a part of a larger set of studies investigating the feasibility of {sup 99}Tc reductive removal from the LAW off-gas condensate. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗