Recent lbnl_es items

Decoding THz‐Driven Dynamic Fingerprints of Ferroelectric Nanotwin Networks

Fri, 19 Jun 2026 00:00:00 +0000

Ultrafast polarization dynamics in ferroelectrics are of considerable interest for high-speed tunable dielectrics and electro-optics. Extended domain wall networks formed in ferroelectric twin nanodomains can support collective dynamics in the terahertz regime but require techniques that track polarization and strain evolution driven by ultrafast stimulus. Here, we use multi-modal probing of THz-pulse-driven excitations in PbTiO₃/SrTiO₃ superlattices by combining X-ray free electron laser measurements that directly tracks lattice changes, with optical second harmonic generation that tracks the electronic potential coupled with the lattice potential. Dynamical phase-field modeling enables fingerprinting of these collective modes as superpositions of domain "breathing" through wall oscillations and polarization "rotations" with still walls. Ultrafast domain wall motion at 0.1-0.5 THz is observed at practical fields of 100 kV/cm with wall velocities of...

Understanding the Cathode Electrochemistry of Humidified Solid‐State Lithium‐Oxygen Batteries

Thu, 18 Jun 2026 00:00:00 +0000

Abstract Lithium‐oxygen batteries (LOBs) possess a high theoretical energy density, making them potential candidates for next‐generation energy storage. However, challenges such as reactive oxygen species‐induced component degradation hinder their practical use. Inorganic solid‐state electrolytes offer an alternative to degradation‐prone aprotic electrolytes, while also protecting lithium anodes from potential atmospheric reactants. This study explores the cathode electrochemistry of solid‐state LOBs using humidified oxygen, which forms an aqueous catholyte during initial cycling, thereby improving cathode‐electrolyte contact. To quantitatively analyze the cathode electrochemistry, a ‘Humidity‐Incorporated’ Differential Electrochemical Gas Monitoring System (HiDEMS) is developed to control humidity and monitor gas consumption and evolution in real time. When studying a Li‐O 2 cell that employs a NASICON‐type Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) solid electrolyte and a porous...

Strong long-wavelength electron-phonon coupling in Ta2Ni(Se,S)5

Thu, 18 Jun 2026 00:00:00 +0000

The search for intrinsic excitonic insulators (EI) has long been confounded by coexisting electron–phonon coupling in bulk materials. Although the ground state of an EI may be difficult to differentiate from density-wave orders or other structural instabilities, excited states offer distinctive signatures. One way to provide clarity is to directly inspect the phonon spectral function for long wavelength broadening caused by phonon interaction with the high velocity EI phason. Here, we report that the quasi-one-dimensional (quasi-1D) EI candidate Ta2NiSe5 shows extremely anisotropic phonon broadening and softening in the semimetallic normal state. In contrast, such behavior is completely absent in the broken symmetry state of Ta2NiSe5 and in the isostructural Ta2NiS5 , where the latter has a fully gapped normal state. By contrasting the expected phonon lifetimes in the BCS and BEC limits of a putative EI, our results suggest that the phase transition in Ta2Ni(Se,S)5 family is closely...

Consistent inclusion of triple substitutions within a coupled cluster based static quantum embedding theory

Thu, 18 Jun 2026 00:00:00 +0000

We have previously proposed the MPCC static embedding framework for quantum chemistry that self-consistently couples a high-level coupled cluster (CC) treatment of the fragment (active region) with a lower level, Møller-Plesset perturbation treatment of the environment. Our initial implementation was limited to single and double (SD) substitutions, with CCSD for the fragment and first-order perturbative SD amplitudes for the environment. Here, we extend the MPCC embedding treatment to triple substitutions, which is essential for achieving chemical accuracy in energy differences. To this end, we employ a CCSDT solver for the fragment subsystem. For the environment subsystem, we construct a perturbative estimate of the triples amplitudes, explicitly accounting for feedback from all fragment amplitudes. The resulting approach is denoted MPCCSDT(pt). We further introduce a more complete formulation in which feedback from the environment amplitudes to the fragment amplitudes is...

Si–Cl Bond Activations at Ni(0) to Give Bimetallic Ni(I) μ _1,2 -Cl–SiR ¹ R ² Complexes that Undergo Selective Hydrogenolyses to R ¹ R ² SiH ₂ Dihydrosilanes

Thu, 18 Jun 2026 00:00:00 +0000

Si–Cl Bond Activations at Ni(0) to Give Bimetallic Ni(I) μ _1,2 -Cl–SiR ¹ R ² Complexes that Undergo Selective Hydrogenolyses to R ¹ R ² SiH ₂ Dihydrosilanes

SmileyLlama: modifying large language models for directed chemical space exploration

Wed, 17 Jun 2026 00:00:00 +0000

Here we show that large language models (LLMs) can be transformed via supervised fine-tuning of engineered prompts into SmileyLlama for exploring the chemical space of drug molecules. We benchmark SmileyLlama against pretrained LLMs and chemical language models trained from scratch for generating valid and novel drug-like molecules, and use direct preference optimization to both improve SmileyLlama’s adherence to a prompt and as part of the iMiner reinforcement learning framework to predict molecules with optimized three-dimensional conformations and high binding affinity to drug targets. By training an LLM to speak directly as a chemical language model, while retaining most of its natural language capabilities, we show that SmileyLlama can reliably generate molecules with user-specified properties rather than acting only as a chatbot with knowledge of chemistry or as a virtual assistant. While SmileyLlama is geared toward drug discovery, the supervised fine-tuning/direct preference...

Enamel nanocrystal misorientation increased with meat-eating and agriculture.

Wed, 17 Jun 2026 00:00:00 +0000

Enamel covers teeth, is the hardest tissue in the vertebrate body and has a complex multiscale structure from nanometres to millimetres1. The structure comprises thin, long hydroxyapatite (Ca5(PO4)3OH) nanocrystals2, 50-70 nm wide, many micrometres long, parallel and bundled into approximately 5-µm-wide rods. The rods undulate and cross into a microscale 'decussation pattern' that toughens enamel by deflecting cracks3,4. However, the crystallographic orientation of enamel nanocrystals is poorly understood. Here we show that the misorientation angle of adjacent nanocrystals varies markedly across 12 primate teeth spanning 9 species, 17.8 million years of evolution and diverse diets. Using a method called Polarization Enabled Large Input of Crystal Angles at the Nanoscale (PELICAN)5, we compare nanocrystals in the same (pre)molar locations and show that misorientation increases with food hardness in extant and fossil non-human apes and monkeys. We compare misorientation...

Electron-doping-induced destabilization of the dimerized insulating state in monolayer IrTe 2

Wed, 17 Jun 2026 00:00:00 +0000

The ability to tune the electronic phases of two-dimensional (2D) materials through external perturbations provides a powerful route to engineer functional nanoscale systems. In particular, the ground state of monolayer... The ability to tune the electronic phases of two-dimensional (2D) materials through external perturbations provides a powerful route to engineer functional nanoscale systems. In particular, the ground state of monolayer (ML) 1T-IrTe 2 is highly sensitive to the interplay between local chemical bonding and global electronic topology, leading to a unique 2 x 1 dimerized insulating phase. Here, we present an angle-resolved photoemission study on the evolution of the electronic structure in ML IrTe 2 induced by in situ Rb adsorption. We find that Rb adsorption suppresses the 2 x 1 dimerized phase in ML IrTe 2 , inducing a clear insulator-to-metal transition. This transition is characterized by a reconstruction of the band topology toward a bilayer-like metallic...

Uranyl Tris(benzoate) Photocatalysts for Site-Selective Hydrocarbon Functionalization.

Tue, 16 Jun 2026 00:00:00 +0000

The uranyl dication ([UO₂]²⁺) is a highly active photocatalyst for the functionalization of inert C_sp3-H bonds by direct hydrogen atom abstraction (HAA). However, photocatalysis by the uranyl ion remains underexplored. Most reports are limited to reactions catalyzed by simple uranyl salts, such as uranyl nitrate [UO₂(NO₃)₂·6H₂O] (U^NO3). We report a set of uranyl tris(benzoate) complexes 1-R containing strongly coordinating and tunable equatorial ligands that resist photodamage and control access to the oxo groups. These catalyst variants with appropriate aryl substituents undergo catalytic reactions at C-H bonds by HAA. The selectivity and reactivity of this step depend on the ligand framework and are distinct from that of U^NO3 or other photoactive oxo complexes, such as decatungstate, that lack ancillary ligands. Finally, consistent with the strong,...

First High-Throughput Evaluation of Dark Matter Detector Materials

Tue, 16 Jun 2026 00:00:00 +0000

We perform the first high-throughput search and evaluation of materials that can serve as excellent low-mass dark matter detectors. Using properties of close to 1000 materials from the Materials Project database, we project the sensitivity in dark matter parameter space for experiments constructed from each material, including both absorption and scattering processes between dark matter and electrons. Using the anisotropic materials in the dataset, we further compute the level of daily modulation in interaction rates and the resulting directional sensitivities, highlighting materials with prospects to detect the dark matter wind. Our methods provide the basic tools for the data-driven design of dark matter detectors, and our findings lay the groundwork for the next generation of highly optimized direct searches for dark matter as light as the keV scale. This represents a major step in the application of results from condensed matter physics to dark matter search design.

Beyond the Pre‐Equilibrium Approximation: Consequences of Elementary Step (Ir)reversibility on the Mechanistic Interpretation of Tafel Slope

Tue, 16 Jun 2026 00:00:00 +0000

The relationship between electrochemical potential and reaction rate-or Tafel slope-is fundamental to the study of multi-step charge transfer reactions. However, despite its importance and ubiquitous use, Tafel slope is seldom interpreted outside of "cardinal" values. The mechanistic interpretation of cardinal Tafel slopes is predicated on the pre-equilibrium approximation (PEA): that the path between the (catalyst) resting state and rate-determining step is in equilibrium. This stringent approximation severely limits opportunities to elicit mechanistic information from electrochemical processes. In this Scientific Perspective, we broaden the existing framework for mechanistic interpretation of Tafel slope through a simple, universal equation that generally describes Tafel slope in terms of elementary-step symmetry factors and approach-to-equilibrium (i.e., approach to PEA accuracy). The predictiveness and mechanistic utility of these theoretical developments are showcased through...

Universality of Shallow Global Quenches in Critical Spin Chains

Tue, 16 Jun 2026 00:00:00 +0000

Measuring universal data in the strongly correlated regime of quantum critical points remains a fundamental objective for quantum simulators. In foundational work, Calabrese and Cardy demonstrated how these data govern the dynamics of certain global quenches to 1+1-dimensional conformal field theories. While the quasiparticle picture they introduce has been widely successful in both theory and experiment, their seminal prediction that the critical exponents are simply encoded in the relaxation rates of local observables is challenging to investigate experimentally. In this Letter, we examine the critical quench dynamics of local observables from two types of readily accessible initial conditions: ground states and finite-temperature ensembles. We identify universal scaling collapses and scaling functions, utilizing a combination of conformal perturbation theory and tensor network numerics. For the finite-temperature quenches, we determine a regime in which the conformal field...

Evidence for Thermodynamically Stable “On-Top” Sulfur Divacancy in Monolayer WS2

Tue, 16 Jun 2026 00:00:00 +0000

Chalcogen vacancies in monolayer transition metal dichalcogenides (TMDs), such as WS2, play a crucial role in various applications ranging from optoelectronics and catalysis to quantum information science (QIS), making their identification and control essential. This study focuses on the WS2 single vacancy and vacancy pairs. Using first-principles computations, we investigate their thermodynamic stabilities and electronic structures. We identify an ”on-top” divacancy configuration where two vacancies sit on top of each other to be the only energetically stable complex with a binding energy of 160 meV. We compute a small difference in electronic structure with a shift of the unoccupied state by 140 meV for the divacancy complex and make note of a similar shift observed experimentally.

Mesoporous peptide frameworks engineered from crystallizable collagen-mimetic peptide amphiphiles

Tue, 16 Jun 2026 00:00:00 +0000

The rational design of porous frameworks with tunable pore dimensions and chemical functionalities is a critical step toward their implementation in diverse applications. While traditional porous materials are typically constructed from abiotic components, there is increasing interest in employing biologically derived building blocks (e.g., peptides and proteins) that offer unmatched structural and functional diversity. Here, we report the construction of crystalline mesoporous frameworks that are self-assembled from amphiphilic collagen-mimetic peptides. Comprehensive structural characterization via microscopy, spectroscopy, and computational techniques provides insights into the assembly packing model, in which hexagonally packed channels are interconnected by antiparallel-aligned collagen triple helices via hydrophobic and electrostatic interactions. Lastly, we demonstrate the functional potential of aCMP frameworks through the encapsulation of various molecular guests,...

Spectral analysis of chemical fluctuations of biomolecules in living cells.

Tue, 16 Jun 2026 00:00:00 +0000

Biomolecules suffering birth and death in living cells often exhibit non-exponential lifetime distributions. However, the chemical dynamics of these biomolecules cannot be described by conventional chemical kinetics or chemical master equations. Here, we present exact results for the mean, time correlation function, and power spectrum of the copy number of biomolecules in living cells, establishing their relationship to product creation dynamics and lifetime distributions. The correctness of these results is confirmed against accurate stochastic simulations. This work establishes the power spectrum of the copy number of biomolecules as a quantitative probe of their intracellular reaction dynamics.

A Prodrug Strategy to Conditionally Trap Therapeutic Payloads for Improved Tumor Retention

Mon, 15 Jun 2026 00:00:00 +0000

Altered extracellular proteolysis has been exploited to selectively activate therapeutics in diseases such as cancer; however, once activated, extracellular drugs can diffuse away, limiting efficacy. We address this challenge by coupling proteolytic activation with membrane tethering to retain drugs within diseased tissue. To accomplish this, we developed “restricted interaction peptides” (RIPs), a delivery platform that leverages elevated proteolytic activity to activate membrane-interacting peptides, localizing cargos near the site of proteolysis. We demonstrate that RIPs can deliver diverse therapeutic cargos, including cytotoxins and radioisotopes. As proof of concept, we engineered “FRIP,” a RIP designed for cleavage by fibroblast activation protein (FAP), an endoprotease upregulated in solid tumors and fibrosis. Efficient P4–P4’ substrate sequences were identified and incorporated into FRIPs. Cell-based studies showed that, upon activation, the peptide adhered to membranes...

Chiral superconductivity from a parent Chern band and its non-Abelian generalization

Thu, 11 Jun 2026 00:00:00 +0000

We propose a minimal model starting from a parent Chern band with quartic dispersion that can describe the spin-valley polarized electrons in rhombohedral tetralayer graphene. The interplay between repulsive and attractive interactions on top of that parent Chern band is studied. We conduct standard self-consistent mean-field calculations, and find a rich phase diagram that consists of metal, quantum anomalous Hall crystal, chiral topological superconductor, as well as trivial gapped Bose-Einstein condensate. In particular, there exists a topological phase transition from the chiral superconductor to the Bose-Einstein condensate at zero temperature. Motivated by the recent experimental and theoretical studies of composite Fermi liquid in rhombohedral stacked multilayer graphene, we further generalize the physical electron model to its composite fermion counterpart based on a field theory analysis. The chiral superconductor phase of the composite fermion becomes the non-abelian...

An Atom-Precise Approach to Damp First-Order Phase Transitions and Its Implications for Neuromorphic Signal Processing

Thu, 11 Jun 2026 00:00:00 +0000

Neuromorphic computing inspired by mammalian intelligence aims to emulate the nonlinear dynamics of biological neurons and synapses to achieve fast, low-energy, and highly efficient information processing. Brain-inspired computing relies on the design and discovery of materials exhibiting nonlinear current-voltage profiles, frequently underpinned by electronic state transitions, to achieve spiking neurons and dynamically tunable synapses. A signature challenge in the design of artificial neurons is controlling the steepness of first-order transitions in active elements, as abrupt transitions are at risk of driving unstable voltage and temperature oscillations, which result in catastrophic device failure. A critical knowledge gap is the lack of structure-function correlations mapping the composition and atomistic structure of crystalline solids to nonlinear dynamical response characteristics. Here, we address the key question of how modification of atomistic structure correlates...

Field-driven ion pairing dynamics in concentrated electrolytes

Thu, 11 Jun 2026 00:00:00 +0000

We investigate ion pairing dynamics in electrolytes driven far from equilibrium using molecular simulations and nonequilibrium rate theory. Focusing on 0.5M LiPF6 in water and acetonitrile under uniform electric fields, we compute transition path theory observables, including reactive fluxes and mean first-passage times of ion pairing. Moreover, we introduce a dynamical proxy of free-ion population, where its field-induced change is strongly correlated with the nonlinear enhancement of conductivity, yielding an increase of 40% at 50 mV/Å in acetonitrile, compared to that of less than 10% in aqueous electrolytes. Further kinetic analysis elucidates that Onsager's classical theory substantially overestimates field-induced enhancement of ion pair dissociation in molecular electrolytes. This discrepancy arises from solvent-mediated dynamical pathways and field-induced dielectric decrement that suppress ion pair dissociation within explicit solvents, highlighting that a faithful...

Solvent effects on triplet yields in BODIPY-based photosensitizers

Thu, 11 Jun 2026 00:00:00 +0000

We employ molecular dynamics simulations and quantum rate theories to elucidate the complex condensed-phase dynamics underpinning triplet-state formation in organic photosensitizers. Using models informed by first-principles calculations complete with a molecular representation of solvents of different polarities, we elucidate the interplay of the internal and environmental interactions underlying triplet yield. We find that triplet yields depend sensitively on the dielectric stabilization of the charge transfer intermediate that facilitates a transition into the triplet manifold. Our results illustrate the importance of molecularly detailed models in understanding the excited-state internal charge-transfer dynamics of photochemically relevant organic molecules.

A dual membrane-adsorption evaporator for solar-powered lithium extraction from complex brines

Wed, 10 Jun 2026 00:00:00 +0000

A reliable supply of lithium is required to meet the increased demand for batteries over the coming decades. In this work, we demonstrated the potential to effectively extract lithium from brines by coupling solar-powered evaporation, adsorption, and membrane technologies together. We first synthesized a three-dimensional adsorptive evaporator by coating a lithium manganese oxide material onto a cotton stick using an easily scalable, one-step method. An osmotic membrane was then installed at the root of the evaporator to enhance the lithium to magnesium selectivity, prevent scaling caused by divalent cations, and thus further increase the water evaporation flux. The operation of the dual membrane-adsorption evaporator is entirely driven by osmosis and capillary force, demanding no extra energy input. The integration of the osmotic membrane was found to increase the lithium to magnesium selectivity over 10-fold to higher than 40. The dual process also produced high lithium to calcium...

Measurement report: Role of organic coating and chemical composition on ice nucleation potential of atmospheric particles in European Arctic

Wed, 10 Jun 2026 00:00:00 +0000

Abstract. Understanding the ice nucleation (IN) potential of Arctic aerosols is critical for predicting their influence on cloud formation and water cycles in this vulnerable region. This study investigates the role of particle composition, organic coatings, and aerosol sources in modulating ice nucleating particle (INPs) abundance across five aerosol samples collected at the Gruvebadet Observatory Station in Ny-Ålesund, Svalbard. The IN potential of Arctic aerosol particles was studied by investigating chemical, morphological, and INP abundance measurements. Single-particle analyses revealed distinct differences in mixing state, organic volume fraction (OVF), and organic coating morphology across samples. OVF distributions were linked to particle origin, with marine-influenced Na-rich particles often exhibiting thin organic coatings, while long-range transported particles showed thicker organic coatings. Biogenic contributions, though variable, were linked to heat-sensitive INPs,...

Point defects in semiconductors: Friends and foes for quantum technologies

Wed, 10 Jun 2026 00:00:00 +0000

Point defects in semiconductors are both a curse and a blessing in microelectronics: they enable the control of electrical conductivity through doping, yet can also act as trapping and recombination centers that degrade device performance. In quantum information science, defects play a similarly dual role. They can be harnessed as spin–photon interfaces enabling the coupling of electronic and nuclear spins to light and the creation of distributed entanglement for quantum networks or used as atomistic scale sensors for quantum sensing. At the same time, defects are a major source of decoherence for superconducting qubits, one of the leading quantum computing platforms. This article discusses how a deeper materials-level understanding of defects can guide the design of improved quantum devices for communication, sensing, and computation.Graphic Abstract

Radiative Electronic Bound States in the Continuum from Defects in Semiconductors

Wed, 10 Jun 2026 00:00:00 +0000

Continuum-buried defect states in semiconductors are generally expected to be optically inactive because of their strong coupling to continuum bands. Here, we show that such defects can instead host radiative electronic bound states in the continuum (BICs) using the silicon G center as a prototypical example. Hybrid functional first-principles calculations with a Hubbard U correction reveal that a localized defect state, initially buried below the valence band maximum (VBM) in the ground state, undergoes exchange-driven energy-level reordering under optical excitation and shifts above the VBM. This exchange-induced transition suppresses nonradiative decay and enables a robust radiative emission. By computing temperature-dependent nonradiative lifetimes and comparing them to experimental photoluminescence (PL) lifetimes, we quantitatively reproduce the observed temperature dependence of the emission. These results uncover a stabilization mechanism for continuum-embedded...

Nanocrystal Geometry Governs Phase Transformation Pathways in Palladium Hydride.

Wed, 10 Jun 2026 00:00:00 +0000

Pathways and structural dynamics of phase transformations impact performance of materials in energy and information storage technologies. Palladium hydride (PdH_x) nanocrystals are an ideal model system for studying solute-induced phase transformations, where elastic energy from lattice mismatch between α-PdH_x and β-PdH_x phases is often considered a key to determining the transformation pathways. α/β-PdH_x interfacial elastic energy is affected by the confined geometry of a nanocrystal. However, how nanocrystal geometry influences phase transformation pathways is largely unknown. Using in situ liquid phase transmission electron microscopy, we directly visualize hydrogenation in Pd nanocrystals with two geometries, a nanocube and a hexagonal nanoplate. Both follow similar sequences of an initially curved nucleus, interface flattening, and reverse-stage nucleation; however, their evolving α/β-PdH_x...

Entropy of Strongly Correlated Electrons in a Partially Filled Landau Level

Wed, 10 Jun 2026 00:00:00 +0000

We use high-resolution chemical potential measurements to extract the entropy of monolayer and bilayer graphene in the quantum Hall regime via the Maxwell relation . Measuring the entropy from down to , we identify the sequential emergence of quantum Hall ferromagnetism, fractional quantum Hall states, and various charge orders by comparing the measured entropy in different temperature regimes with theoretical models. At the lowest temperature of we perform a detailed study of the entropy near even-denominator fractional quantum Hall states in bilayer graphene, and comment on the possible topological origin of the observed excess entropy.

Polyolefin blends with co-continuous architectures enabled by dynamic covalent crosslinking

Wed, 10 Jun 2026 00:00:00 +0000

Blending polymers produces brittle materials due to macrophase separation and poor interfacial adhesion, which is exemplified by mixtures of polyolefins. This presents a formidable challenge for the mechanical recycling of mixed plastic waste. Here, we demonstrate that dynamic covalent crosslinking of immiscible polyolefin blends creates macrophase separated co-continuous architectures, yet they display excellent mechanical properties, which challenges the conventional wisdom regarding morphology-property relationships in polymer blend compatibilization. We find that the position and orientation of dynamic crosslinks and their influence on crystallinity are key to understanding the structure-morphology-property relationships. In particular, high-resolution microscopy imaging reveals alignment of crystallite planes with strong orientational preference, particularly at polymer-polymer interfaces, which contribute to material performance. We further demonstrate that changes in crosslinker...

Ultra-grain refinement creates FCC pure cobalt with high strength and high ductility

Wed, 10 Jun 2026 00:00:00 +0000

Although pure cobalt is generally known to have a hexagonal close-packed (HCP) structure at room temperature, we show that its high-temperature face-centered cubic (FCC) phase can be strongly stabilized through grain refinement, resulting in FCC pure cobalt at room temperature. Ultrafine-grained (UFG) FCC cobalt exhibits a hierarchical microstructure consisting of dense stacking fault (SF) networks in the dominant FCC grains and numerous SFs and thin FCC layers within a few HCP plates. This unique microstructure leads to a high tensile strength exceeding 1 GPa, together with a tensile elongation of over 35%, thereby surpassing the well-known strength–ductility trade-off of pure metals. In-situ synchrotron X-ray diffraction revealed that the UFG FCC cobalt exhibited a markedly enhanced deformation-induced FCC→HCP martensitic transformation, which provided sustained strain hardening through the transformation-induced plasticity (TRIP) effect. Furthermore, ultra-grain refinement...

A Lens into the Cu Nanograin by In Situ Vibrational Spectroscopy

Wed, 10 Jun 2026 00:00:00 +0000

Cu-based catalysts are uniquely capable of C-C coupling during electrochemical CO₂ reduction (CO₂R), yet further mechanistic understanding remains hampered by the lack of spectroscopically resolved descriptors that demonstrate how surface adsorbates emerge and evolve within their catalytic environment. Here, we correlate in situ surface-enhanced Raman spectroscopy (SERS) and surface-enhanced infrared absorption spectroscopy (SEIRAS) to resolve the potential-dependent dynamics during CO₂R on Cu nanograin catalysts. By building on previous benchmarking of low overpotential performance and nanograin structural evolution, we offer a diagnostic framework linking vibrational signatures to catalytic function, unveiling which species appear, persist, and turnover as the electrified surface and interfacial environment evolve under bias. The onset of linear CO is marked below -0.45 V, coincident with persistent adsorbed *OH/*O domains beyond the CO₂R...

Chemistry of Sugar Formation in the Gas Phase: Following the Activated Aldehyde

Tue, 9 Jun 2026 00:00:00 +0000

Sugars are produced by living organisms, and are required building blocks for life as we know it, which raises the foundational question of how sugars formed in a prebiotic environment. The abiotic formose reaction produces sugars from formaldehyde, but our understanding of its initiation step remains murky, with chemists invoking the concept of an "activated aldehyde" to seed this reaction. Singlet hydroxycarbenes, high-energy isomers of aldehydes, were recently reported to facilitate sugar formation under cold, nonaqueous conditions relevant to interstellar environments. We generate singlet methylhydroxycarbene (¹CH₃-C̈-OH) from the photodissociation of pyruvic acid and experimentally measure its gas-phase reaction with d₄-acetaldehyde using multiplexed photoionization mass spectrometry. The C₄H₄D₄O₂ isomer d₄-acetoin is the sole product, which we kinetically link to the reactant...

The Chemistry of Carbenes: New Insights from the Gas Phase

Tue, 9 Jun 2026 00:00:00 +0000

This review describes insights obtained from recent studies of unimolecular and bimolecular reactions of small carbenes in the gas phase and cryogenic environments. Following a description of what determines the singlet-triplet splitting in carbenes, we discuss the challenges involved in producing carbenes in concentrations sufficient for studying their reactions. We document the methods developed for their preparation and the array of spectroscopic techniques available for their characterization. The review emphasizes recent progress in studies of hydroxycarbenes and small alkyl carbenes that easily isomerize to more stable isomers. The studies of unimolecular reactions of hydroxycarbenes show how quantum mechanical tunneling determines their lifetimes. A new carbonyl-ene mechanism has been demonstrated in the biomolecular reactions of hydroxymethylene and methylhydroxycarbenes. We evaluate the impact of these new results on chemical processes relevant to atmospheric, planetary,...

Dara: Automated Multiple-Hypothesis Phase Identification and Refinement from Powder X‑ray Diffraction

Tue, 9 Jun 2026 00:00:00 +0000

Powder X-ray diffraction (XRD) is a foundational technique for characterizing crystalline materials. However, the reliable interpretation of XRD patterns, particularly in multiphase systems, remains a manual and expertise-demanding task. As a characterization method that only provides structural information, multiple reference phases can often be fit to a single pattern, leading to potential misinterpretation when alternative solutions are overlooked. To ease humans' efforts and address the challenge, we introduce Dara (data-driven automated Rietveld analysis), a framework designed to automate the robust identification and refinement of multiple phases from powder XRD data. Dara performs an exhaustive tree search over all plausible phase combinations within a given chemical space and validates each hypothesis using the BGMN Rietveld refinement routine. Key features include structural database filtering, automatic clustering of isostructural phases during tree expansion, and peak-matching-based...

Celebrating 25 Years of Scientific Discoveries in Physical Chemistry Supported by the ACS Petroleum Research Fund

Tue, 9 Jun 2026 00:00:00 +0000

Celebrating 25 Years of Scientific Discoveries in Physical Chemistry Supported by the ACS Petroleum Research Fund

Ion correlations explain kinetic selectivity in diffusion-limited solid-state synthesis reactions

Tue, 9 Jun 2026 00:00:00 +0000

Establishing viable solid-state synthesis pathways for novel inorganic materials remains a major challenge in materials science. Previous pathway design methods using pairwise reaction approaches have navigated the thermodynamic landscape with first-principles data but lack kinetic information, limiting their effectiveness. This gap leads to suboptimal precursor selection and predictions, especially for reactions forming competing phases with similar formation energies, where ion diffusion is a critical influence. Here we demonstrate an inorganic synthesis framework by incorporating machine learning-derived transport properties through ‘liquid-like’ product layers into a thermodynamic cellular reaction model. In the Ba–Ti–O system, known for its competitive polymorphism, we obtain accurate predictions of phase formation with varying BaO:TiO2 ratios as a function of time and temperature. We find that diffusion–thermodynamics interplay governs phase compositions, with cross-ion...

Transient Pulse-Response Time-of-Flight Mass Spectrometry for Complex, Deactivating Heterogeneous Catalytic Systems: Application to Ethane Dehydroaromatization

Tue, 9 Jun 2026 00:00:00 +0000

The study of complex, multistep bond-forming and -breaking reactions in heterogeneous catalytic systems often encounters challenges associated with the involvement of large numbers of intermediates among branching pathways. Kinetic information obtained from traditional steady-state measurements can be complemented with that from time-resolved methods to uncover details of the underlying chemistry. Herein, we describe an approach for tracking the complete time-resolved chemical composition (ca. 4–200 u) of a reactor effluent in response to a reactant pulse. We use a six-port rotary valve with a metered sampling loop to pulse reactants at ambient pressure into a flow reactor packed with a catalyst bed within the isothermal region of a heated furnace. The temporal evolution of effluent species is tracked using time-resolved molecular-beam time-of-flight mass spectrometry. We highlight the possibilities that this method has to offer by studying the complex bifunctional mechanism of...

High-Resolution Time-Resolved PEPICO with Tunable Vacuum Ultraviolet Photoionization

Tue, 9 Jun 2026 00:00:00 +0000

Recently we presented a new time-resolved, double-imaging photoelectron photoion coincidence (i²PEPICO) spectrometer for the study of chemical reactions using fixed frequency, single-photon vacuum ultraviolet ionization. Here we describe new capabilities and insights from this instrument when coupled with tunable ionizing radiation. We interrogate the gas expansion dynamics of a side-sampled chemical reactor tube, revealing clear evidence for viscous flow in the expansion before ionization. Cation imaging can be used to restrict detected signal to only the direct molecular beam, removing contributions from background and reflected gases. We characterize the peak shape and mass resolution of the instrument, provide new insight and clarification regarding collection efficiencies, and consider the noise sources and resulting signal-to-noise in PEPICO experiments. We quantify the temporal instrument response function and show that velocity map imaging of cations...

Author Correction: An autonomous laboratory for the accelerated synthesis of inorganic materials

Tue, 9 Jun 2026 00:00:00 +0000

Correction to: Naturehttps://doi.org/10.1038/s41586-023-06734-w Published online 29 November 2023 Following publication of this article, concerns were raised about the unambiguous identification of the compound structures using diffraction as well as the original claims of material novelty. We acknowledge that the original claims of material novelty were subject to misinterpretation—their intention was to indicate that the materials were new to the prediction platform, not necessarily new to science. The article text has been updated to reflect this in the HTML and PDF versions of the article. For a detailed breakdown of the textual changes, please see the annotated PDF article file available as Supplementary Information accompanying this amendment. In addition, we have manually re-analyzed the diffraction patterns and have confirmed that the prediction platform came to the correct conclusion in 36 of its 40 reported successes, with 4 compounds being inconclusive. This re-analysis...

Fluoroform (CHF3) Production from CF3CHO Photolysis and Implications for the Decomposition of Hydrofluoroolefins and Hydrochlorofluoroolefins in the Atmosphere

Tue, 9 Jun 2026 00:00:00 +0000

Hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs) are the leading synthetic replacements for compounds successively banned by the Montreal Protocol and amendments. HFOs and HCFOs readily decompose in the atmosphere to form fluorinated carbonyls, including CF₃CHO in yields of up to 100%, which are then photolyzed. A long-standing issue, critical for the transition to safe industrial gases, is whether atmospheric decomposition of CF₃CHO yields any quantity of CHF₃ (HFC-23), which is one of the most environmentally hazardous greenhouse gases. This comprehensive experimental investigation employs purpose-built photoionization mass spectrometry, Fourier-transform infrared, and microwave spectroscopy techniques and confirms production of CHF₃ following excitation at a tropospherically relevant wavelength (λ = 308 nm) and under atmospheric pressure conditions. Pressure-dependent CHF₃ quantum (Φ) and molar (Y)...

Reducing Flavin and Ubiquinone Headgroups with Silicon Nanowire Photocathodes

Fri, 5 Jun 2026 00:00:00 +0000

Photosynthetic biohybridsa structure composed of semiconducting electrodes and carbon dioxide-fixing autotrophs which can be energized by the electrodeoffer a promising platform for selective CO2 reduction. However, studying the charge-transfer mechanisms from the semiconductor to the cell proves challenging due to a variety of simultaneous processes. Therefore, to deconvolute the system to understand photoelectrochemical performance, we employ model systems composed of a subset of the electron-transfer pathway. Here, we photoelectrochemically reduced ubiquinone-0 (UQ0) and riboflavin (Rf) (the head groups of ubiquinone-8/10 and flavin mononucleotide/flavin adenine dinucleotide) using Pt-decorated n+p-silicon nanowires, a robust catalytic architecture. Under irradiation with 100 mW cm–2 red light (740 nm), UQ0 and Rf were reduced with onset potentials of 0.876 V vs the reversible hydrogen electrode (VRHE) and 0.691 VRHE, respectively. In addition, UQ0 achieved a maximum Faradaic...

An interactive machine learning platform for analyzing multi-particle coincidence data from cold target recoil ion momentum spectroscopy

Thu, 4 Jun 2026 00:00:00 +0000

We present SCULPT (Supervised Clustering and Uncovering Latent Patterns with Training), a comprehensive software platform for analyzing tabulated high-dimensional multi-particle coincidence data from Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) experiments. The software addresses critical challenges in modern momentum spectroscopy by integrating advanced machine learning techniques with physics-informed analysis in an interactive web-based environment. SCULPT implements uniform manifold approximation and projection for non-linear dimensionality reduction to reveal correlations in high-dimensional data. We also discuss potential extensions to deep autoencoders for feature learning and genetic programming for automated discovery of physically meaningful observables. A novel adaptive confidence scoring system provides quantitative reliability assessments by evaluating user-selected clustering quality metrics with predefined weights that reflect each metric's robustness....

Revealing ultrafast proton-transfer-mediated autoionization as a source of low-energy electrons in hydrogen-bonded systems

Thu, 4 Jun 2026 00:00:00 +0000

Ionizing radiation can trigger ultrafast proton transfer, a central mechanism in many chemical and biological functions, that in turn can enable or suppress electron relaxation processes and consequently cause abrupt changes in the reaction pathway. This study combines theory and experiment to probe ultrafast relaxation and dissociation in water dimers following inner- and outer-valence photoionization. By tracking electron and nuclear motion simultaneously, we reveal competing fragmentation pathways that produce low-energy electrons, which are key agents in radiation-induced chemistry, including DNA damage. While low-energy electrons are known to arise via intermolecular Coulombic decay, here we identify a faster relaxation mechanism gated by proton transfer following inner-valence ionization, which we call proton-transfer-mediated autoionization. Occurring within 10 femtoseconds, this process alters fragmentation outcomes, yielding either D3O+ + OD+ or D2O+ + D2O+, depending...

The Cascade Effectiveness of 3‑Terminal Tandem Photocathode Architectures as Applied to CO2 Reduction

Thu, 4 Jun 2026 00:00:00 +0000

Cascade catalysis for photoelectrochemical CO2 reduction (CO2R) decouples the overall reaction into sequential steps occurring on separately optimized catalysts (for example, Ag and Cu) between which an intermediate species such as CO is transferred. A 3-terminal tandem (3TT) photovoltaic architecture advantageously holds two different catalytic regions at different potentials under a single illumination source, but its overall efficiency is low. Using a stochastic reaction-diffusion model, we have examined 3TT photocathode design principles, focusing on the coupling of surface chemistry and transport of CO both inside the boundary layer and outward, into the bulk electrolyte. We find that ensuring that the lateral diffusion distance within the boundary layer is short compared to the boundary layer thickness and controlling bulk flow are key, with interdigitated designs showing an overall conversion efficiency improvement by 2 orders of magnitude compared to the side-by-side case...

Plasmonic polaron in self-intercalated 1T-TiS2

Wed, 3 Jun 2026 00:00:00 +0000

Electron-boson coupling is central to a comprehensive understanding of the diverse physical phenomena emerging from many-body interactions. Yet less attention has been paid to how plasmons, collective bosonic modes of electron density oscillation, interact with conduction electrons and how external parameters can tune this interaction. Here, we present a clear display of composite quasiparticles stemming from electron-plasmon coupling, known as the plasmonic polaron, in self-intercalated 1T-TiS2, by using angle-resolved photoemission spectroscopy (ARPES), high-resolution electron energy loss spectroscopy (HR-EELS) and first-principles calculations. The single particle spectral function exhibits a distinctive plasmon-loss satellite with the same characteristic energy scale determined by HR-EELS measurements. The bosonic energy scale of plasmonic polaron is tunable by controlling charge carrier density and temperature, distinguishing itself from conventional polarons arising from...

2D Magnetic Materials for Sensor Technologies

Wed, 3 Jun 2026 00:00:00 +0000

Two-dimensional (2D) magnetic materials have emerged as a promising platform for next-generation sensing technologies due to their atomic thickness, tunable magnetic properties, and compatibility with van der Waals heterostructures. Rapid progress in material discovery, synthesis, and device integration has expanded opportunities for compact, low-power, and highly sensitive sensor platforms. This review examines selected sensing mechanisms enabled by 2D magnetic materials, highlighting recent experimental advances and emerging device concepts. Current limitations and challenges such as environmental stability, scalability, and room-temperature operation are considered in the context of ongoing research efforts. By examining these approaches, this review aims to provide insight into the current development and potential of 2D magnetic materials for sensing technologies. This review is organized to first introduce the fundamental properties and challenges of 2D magnetic materials,...

Light‐Induced Lattice Coherence and Emission Enhancement in PTM‐Passivated CsSnI3 Perovskites

Wed, 3 Jun 2026 00:00:00 +0000

Abstract Metal halide perovskites continue to lead in optoelectronic applications, but the toxicity of lead has driven efforts to identify environmentally benign alternatives. Cesium tin iodide (CsSnI 3 ) is one such, with a direct bandgap and near‐infrared emission, though its performance is limited by instability. We show that phthalimide (PTM) passivation during single crystal growth enhances optical output and stability. Under continuous excitation, PTM‐passivated microscale crystals show up to one order of magnitude increase in photoluminescence (PL) quantum yield, accompanied by reversible sharpening of a low‐frequency Raman mode associated with Cs⁺ rattling. This reveals dynamic, light‐induced lattice reordering that passivates trap states and enhances radiative recombination. Mechanical grinding yields nanocrystals with redshifted, narrowed PL, consistent with a relaxed polymorph and reduced inhomogeneous broadening. Despite increased surface area, PTM remains effective...

In Situ Study of Resistive Switching in a Nitride‐Based Memristive Device (Adv. Funct. Mater. 31/2026)

Wed, 3 Jun 2026 00:00:00 +0000

Nitride‐Based Memristive Devices In their Research Article (10.1002/adfm.202517173), Di Zhang, Aiping Chen, and co‐workers use in situ transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) techniques to probe the ionic migration process: A large number of oxygen vacancies (V_O˙˙) migrate under the electric field through grain boundaries of the TiOx phase. The study presents a new perspective of the interface‐dominated resistive switching process for novel energy‐efficient microelectronic device applications.

Deciphering Experimental Reactivity of Metal Clusters Toward N2 Activation Using Graph Neural Networks

Wed, 3 Jun 2026 00:00:00 +0000

Machine learning (ML) analysis of gas-phase metal cluster reactivity has emerged as a pivotal approach in this field. However, existing ML studies relying on electronic properties have primarily focused on discrete features, with less consideration of continuous structural factors that also govern cluster reactivity. Here, we present the first graph neural network (GNN) framework to model N₂ activation reactivity across 245 metal clusters, combining DFT-optimized structures with experimental reaction rates collected from the literature and a public data set. Through encoding both topological connectivity and atomic-level features (e.g., natural charge, valence electron occupancy, and atomic number), the graph isomorphism network (GIN) achieves superior predictive performance on reaction rates of unseen clusters. Explainable analysis reveals that natural charge redistribution likely serves as the primary mechanism for ligand-mediated reactivity modulation. Furthermore,...

CFD simulation of anisotropic heat transfer and water vapor condensation in gas diffusion layer of a fuel cell

Wed, 3 Jun 2026 00:00:00 +0000

Effective water and thermal management are crucial for maximizing the performance of proton exchange membrane fuel cells (PEMFCs). This study presents a robust non-isothermal model that integrates two-phase flow, species transport, and heat and mass transfer phenomena to investigate water generation, accumulation, and permeation mechanisms within the gas diffusion layer (GDL) of PEMFCs. Utilizing X-ray computed tomography (XCT) reconstruction, a 2D structure of the Freudenberg GDL is generated. The model incorporates anisotropic thermal conductivity, distinguishes between in-plane and through-plane K IP K TP ratios, and demonstrates its importance to temperature distribution and subsequent condensation rate within the GDL. Additionally, our parametric analysis evaluates the effects of GDL thermal conductivity, current density, operating temperature, and pressure on water condensation and transport processes in PEMFCs. Key findings include the identification of distinct phases...

Plutonium(III) versus uranium(III) and samarium(III) in small molecule activation chemistry

Fri, 29 May 2026 00:00:00 +0000

We report the PuIII complex, [PuIII(CpMe4)3] (1-Pu), and demonstrate its differences in small molecule reactivity compared to the UIII and SmIII analogs, [UIII(CpMe4)3] (1-U) and [SmIII(CpMe4)3] (1-Sm), respectively. 1-Pu reductively cleaves the small molecule (PhS)2, affording a PuIII complex, [{PuIII(CpMe4)2}2(μ-SPh)2] (2-Pu), while retaining the PuIII center and eliminating (CpMe4)2 as a by-product, a fingerprint of a sterically induced reduction (SIR) reaction. Sm is often used as a surrogate for Pu, but the analogous [SmIII(CpMe4)3], (1-Sm), is unreactive. The (PhS)2 cleavage by 1-U proceeds solely via a metal-based oxidation (i.e., UIII → UIV), to form [UIV(CpMe4)3(SPh)] (3-U). Only 1-U reacts with (PhHN)2, affording the reductive cleavage product, [UIV(CpMe4)3(NHPh)] (4-U). The difference in reactivity of 1-Pu compared to complexes 1-Sm and 1-U was unexpected, and since SIR chemistry can enable complexes to participate in otherwise impossible reductive transformation of...

Balancing moisture and oxygen can match the crystallization dynamics of inert halide perovskite processing

Thu, 28 May 2026 00:00:00 +0000

Balancing moisture and oxygen replicates inert crystallization dynamics in antisolvent-free halide perovskite processing under ambient conditions. Understanding crystallization in ambient environments is essential for scaling the fabrication of halide perovskite solar cells. Antisolvent-free perovskite deposition offers improved compatibility with high-throughput processing but introduces distinct crystallization dynamics relative to the more ubiquitous use of antisolvents in lab-scale perovskite fabrication. These dynamics are driven by interactions between solutes, solvent and the deposition environment. Using in situ wide-angle X-ray scattering during spin-coating and annealing, we demonstrate how relative humidity (RH) and oxygen, can be tuned to drive polytype evolution during ambient crystallization of formamidinium lead iodide to match that of inert synthesis and achieve comparable film and device quality. In an inert (N 2 ) environment, we find that perovskite films follow...

Multi-modal characterization of nitrate reduction nano-catalysts with periodic strain distribution

Wed, 27 May 2026 00:00:00 +0000

Strain engineering serves as a pivotal strategy to optimize catalytic activity in electrocatalysis. However, the catalyst sizes under industrial conditions are usually large and even beyond nanometer regime. The critical methodological limitations on strain imaging of such catalysts with both large field of view and high spatial resolution obscure the mechanistic understanding of strain-performance correlations. Here, we present an optimized four-dimensional scanning transmission electron microscopy (4D-STEM) method to acquire strain mapping of both bulk and surface across particles up to 500 nm with 0.6 nm spatial resolution and 0.55% precision. We observe the ripple-like periodic strain coupled with elemental fluctuations inside a perovskite-type hydroxide CuCoSn(OH)6 and find it correlated to electrocatalytic nitrate reduction (NO3–RR) absorption energy to achieve the 92.6% Faradaic efficiency and long-term test over 1000 h at membrane electrode assembly (MEA) for ammonia electrosynthesis....

Chiral spin liquid and quantum phase transition in the triangular-lattice Hofstadter-Hubbard model

Wed, 27 May 2026 00:00:00 +0000

Recent advances in moiré engineering motivate the study of lattice models of strongly correlated electrons subjected to substantial orbital magnetic flux. We analyze the triangular-lattice Hofstadter-Hubbard model at one-quarter flux quantum per plaquette and a density of one electron per site, where a chiral spin liquid phase may exist between weak-coupling integer quantum Hall and strong-coupling 120∘ antiferromagnetic phases. We use matrix product state methods and analytical arguments to investigate this model compactified to cylinders of finite circumference. We uncover a glide particle-hole symmetry operation which, we argue, is spontaneously broken at the quantum Hall to spin liquid transition on odd-circumference cylinders. We numerically verify the spontaneous symmetry breaking and further demonstrate that this transition is associated with algebraic long-range correlations of various spin-singlet, charge-neutral operators. For even-circumference cylinders, the transition...

Tuneable electronic coupling in linked bis(cubane) cobalt-oxo clusters

Wed, 27 May 2026 00:00:00 +0000

A family of cobalt-oxo bis(cubane) complexes wherein each subunit is derived from the Co₄O₄ cubane, a known water oxidation catalyst, was synthesized. Both 4,4'-bipyrdine and pyrazine were demonstrated to serve as viable bridging ligands. Through an analysis of their half-wave splitting potentials, it was determined that pyrazine-bridged bis(cubane)s exhibit inter-cubane electronic coupling, and that this coupling may be tuned through ligand substitution. Electrostatic contributions to the half-wave splitting potentials were evaluated and found to result in "non-conformist" behavior related to the ion-pairing ability of the electrolytes.

Modulating coordinate site occupancy in high-entropy spinel electrocatalysts

Wed, 27 May 2026 00:00:00 +0000

High entropy spinel oxides provide a versatile platform for electrocatalysis because multiple metal cations can be incorporated into a single crystalline lattice, enabling tunable electronic structures. However, controlling how these cations distribute between tetrahedral and octahedral coordination sites remains a major challenge, limiting rational catalyst design. Here, we modulate cation coordination site occupancy between tetrahedral and octahedral sites in a Co–Fe–Cr–Mn–Ni framework by introducing a sixth cation (Zn, Ga, Mg, or Al) with distinct site preference energies. Using density functional theory, synchrotron X-ray absorption spectroscopy, and magnetic circular dichroism, we demonstrate that Zn preferentially occupies tetrahedral sites, driving increased octahedral occupancy of cobalt. This redistribution increases the population of octahedrally coordinated cobalt in mixed oxidation states, enhances electrical conductivity, and improves oxygen evolution reaction activity....

Native Chemical Ligation of Peptoid Oligomers

Wed, 27 May 2026 00:00:00 +0000

Bioorganic chemists are inspired by natural biopolymers to design peptidomimetic oligomers that can exhibit sequence-structure-function relationships. Biomimetic polymers can be synthesized to incorporate a specific sequence of nonbiological monomer units using a variety of iterative solution-phase or solid-phase reaction schemes. These protocols generally provide access to a vast diversity of oligomeric compounds but are limited with respect to their ability to attain protein-like chain lengths. This constraint can preclude access to sequence-defined synthetic macromolecules with sufficient sizes required to exhibit tertiary structure and other protein-mimetic attributes. In contrast, peptide chemists have overcome this limitation by developing convergent synthetic methods, such as native chemical ligation, to join individual, smaller peptide chains together to make larger peptides or full proteins. A similar convergent approach is needed to establish efficient synthetic routes...

One-Body Properties and Their Perturbative Accuracy with Aufbau Suppressed Coupled Cluster Theory

Wed, 27 May 2026 00:00:00 +0000

We derived and implemented the calculation of the one-body reduced density matrix for Aufbau suppressed coupled cluster theory, from which excited state natural orbitals and one-body properties, like atomic populations and dipole moments, are obtained. We utilized the natural orbitals to refine the ASCC solution for simple valence and Rydberg systems, exploring the process of repeatedly solving the ASCC equations in successive natural orbital bases to achieve independence from the starting molecular orbitals. For dipole moments in small molecules where high-level comparison data is available, we find that the accuracy of ASCC essentially matches that of linear response and equation-of-motion coupled cluster as long as care is taken to preserve the response's perturbative completeness.

Zircon Constraints on the Eruptive Sequence and Magma Evolution of Rhyolites at South Sister Volcano, Oregon

Thu, 21 May 2026 00:00:00 +0000

Abstract We present 230 Th‐ 238 U crystallization ages and trace element compositions for zircons spanning the late Pleistocene to Holocene rhyolite eruptive record at South Sister volcano in the central Oregon Cascade Range. Most zircon ages are between 100 and 20 ka, with very few in secular equilibrium (>350 ka). The weighted mean of zircon ages for the two oldest South Sister rhyolites, 31.5 ± 2.1 and 39.1 ± 2.4 ka, are significantly younger than the associated 40 Ar/ 39 Ar ages, 47.4 ± 9.7 and 51.4 ± 9.7 ka. We propose that these 40 Ar/ 39 Ar dates, performed on plagioclase separates, are compromised by a subtle amount of excess Ar and therefore the younger weighted mean zircon ages yield more reliable eruption ages. These results imply that the interval of rhyolite eruption at South Sister during the late Pleistocene was both shorter and more productive than previously thought and that eruption at South Sister...

Design and commissioning of a new synchrotron beamline dedicated to X‐ray footprinting mass spectrometry

Thu, 21 May 2026 00:00:00 +0000

The structural biology method of X-ray footprinting mass spectrometry (XFMS) is available at two national synchrotron beamlines in the USA: one at the Advanced Light Source (ALS) on the West Coast and the other at the National Synchrotron Light Source II on the East Coast. XFMS is a solution-state technique that utilizes oxidative modifications of proteins at micromolar concentrations in aqueous buffer to extract structural information. X-rays are employed to generate hydroxyl radicals in situ, which covalently modify specific protein side chains. These modifications are subsequently quantified using liquid chromatography and mass spectrometry. Ratiometric changes in modification levels between two protein states (e.g. with and without ligand) generate a relative solvent accessibility map of the protein pairs, which serves to reveal structural features. Up until recently, the XFMS capability was available as part of a shared program at the ALS without a dedicated beamline. In...

The Magmatic‐Hydrothermal System of the Three Sisters Volcanic Cluster, Oregon, Imaged From Field Gravity Measurements

Thu, 21 May 2026 00:00:00 +0000

Abstract From 2019 to 2024, gravity surveys were conducted at the Three Sisters volcanic cluster (TSVC), measuring 246 gravity sites using a spring relative gravimeter. We calculated the residual Bouguer anomaly and identified three main zones with negative anomalies, ranging from −4 to −8 mGal, located southwest and west of South Sister, within an area that has been uplifting for the past two decades. After inversion, we obtain a 3D density model of the subsurface and identify low‐density bodies extending from the surface down to 3 km. We estimate a total of 15 k of crustal bodies with density close to 2 g/ that could store up to 5 k of water, forming an extensive hydrothermal system beneath the TSVC. We explore the possible combinations of melt compositions and temperatures that could create a bulk density close to our reference crustal density (2.5 g/) using MELTS thermodynamic simulations. Our results indicate that a magmatic mush with as little...

Spin Polarization from Circularly Polarized Light Induced Charge Transfer

Fri, 15 May 2026 00:00:00 +0000

We show how a spin polarization can be generated through the photoinduced electron transfer of an achiral donor-acceptor complex following chiral light excitation. In particular, we illustrate the basic energetic and symmetry requirements for chirality induced spin selectivity where the chirality emerges from the electronic degrees of freedom following excitation with circularly polarized light. We study this effect in a simple model of a metalloporphyrin complex with an axial acceptor ligand using quantum mechanical rate theories and numerical simulations. We find that the spin polarization emerges due to the selective excitation of a ring current within the porphryin, breaking the degeneracy of the two degenerate spin states. The resultant spin polarization increases with the spin orbit coupling between the metal in the porphyrin and the axial ligand, and is transient, with a lifetime dependent on the rate of dephasing from the Jahn-Teller distortion mode. This proposed effect...

Trivalent titanium in high-titanium lunar ilmenite

Fri, 15 May 2026 00:00:00 +0000

Lunar mare basalts are often rich in titanium, hosted predominantly within the mineral ilmenite (Fe2+Ti4+O3). Here, we examine ilmenite in a ~ 3.8 billion-year-old mare basalt (Apollo rock 75035) using high-resolution electron microscopy and electron energy loss spectroscopy. A key finding is that 75035 ilmenite is itself enriched in Ti, beyond the end member of the conventional solid solution series. Using energy loss near-edge spectroscopy, we determine that the excess Ti is trivalent, with Ti3+ accounting for 13% of the total Ti content. This discovery confirms the presence of trivalent Ti in lunar ilmenite, long hypothesized based on the Moon’s reducing environment. Accounting for the change in implied stoichiometry, a review of literature data suggests that Ti3+ may be present in ilmenite across a wide range of lunar samples. We extrapolate known relationships from the literature to connect Ti3+ to redox conditions, estimating the oxygen fugacity during crystallization...

A photochargeable semiconductor for highly efficient dehydrogenative coupling of amines

Fri, 15 May 2026 00:00:00 +0000

The development of materials with high photocatalytic efficiency is essential for sustainable chemical transformations. Here we introduce photochargeable zinc indium sulfide nanocrystals with notable charge storage capacity, enabling highly efficient photocatalytic dehydrogenative coupling of amines. Combined with a nickel cocatalyst, the nanocrystals deliver diamines and hydrogen at rates exceeding 120 mmol per gram of photocatalyst per hour, with > 95% selectivity and an apparent quantum efficiency of up to 39.4% under ambient conditions. The system exhibits excellent scalability, demonstrated by a reaction on a 20-g scale, and broad versatility in promoting amino acid ester coupling and polymerization reactions with concurrent hydrogen evolution. Mechanistic studies attribute the photocharging capability of zinc indium sulfide nanocrystals to in situ-generated trap states such as sulfur vacancies, which extend hydrogen production into the dark catalytic cycle and enhance...

Orbital-Dependent Coulomb Drag in Electron-Hole Bilayer Graphene Heterostructures

Fri, 15 May 2026 00:00:00 +0000

We report Coulomb drag studies in an electron-hole bilayer graphene heterostructure in a magnetic field, where the orbital, spin, and valley degrees of freedom are lifted by the combined effects of exchange interaction, Zeeman energy, and a vertical displacement field. Our device enables the application of a large vertical displacement field across both layers. In addition to the well-established strong Coulomb drag between the Landau levels with an orbital quantum number N=0, we observe a Coulomb drag signal between the N=1 Landau levels under a suitable vertical displacement field. As the vertical displacement field increases further, the Coulomb drag signal between N=1 Landau levels weakens, and a Coulomb drag signal emerges between the N=0 and N=1 Landau levels. These findings suggest the important roles of the orbital index and the vertical displacement field in interlayer Coulomb interaction within the quantum Hall regime of coupled bilayer systems.

Identification of Solid-Electrolyte Interphase Species by Joint Characterization of Li-Ion Battery Chemistry by Mass Spectrometry and Electrochemical Reaction Networks.

Thu, 14 May 2026 00:00:00 +0000

The formation and stability of the solid-electrolyte interphase (SEI) play central roles in determining the long-term performance and safety of modern electrochemical energy storage systems. Despite decades of research, the SEI's heterogeneous, dynamic, and multiphase nature has defied comprehensive molecular-level characterization, creating a critical knowledge gap that limits rational battery design. In this work, we introduce a computational-experimental framework that integrates high-throughput quantum chemistry calculations, data-driven electrochemical reaction networks (eCRNs), stochastic algorithms, and laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (LDI-FTICR-MS) to unravel SEI formation in carbonate-based electrolytes without imposing predefined mechanisms. We constructed the most comprehensive eCRN to date, spanning over 10,000 species and 209 million reactions. Through stochastic network analysis, we successfully recovered 27...

Single domain spectroscopic signatures of a magnetic kagome metal

Thu, 14 May 2026 00:00:00 +0000

Magnetic kagome metals host complex electronic states and real-space magnetic textures, but their small and temperature-dependent magnetic domains make experimental access difficult. Here we show that micro-focused circular-dichroic photoemission spectroscopy enables spectroscopic access to individual magnetic domains in the kagome metal DyMn6Sn6 at low temperature. By tuning to element-specific electronic states, we image domain contrast associated with Dy 4f levels and detect corresponding signatures from Mn core states. The energy dependence of the dichroic response is consistent with modeling and indicates ferrimagnetic alignment between Dy and Mn local moments. Measurements of Mn 3d-derived valence bands, supported by first-principles calculations, reveal features related to orbital magnetization. These results establish element- and orbital-resolved spectroscopy of single magnetic domains and enable studies of magnetic textures and electronic structure in complex magnetic...

Revealing short- and long-range Li-ion diffusion in Li 2 MnO 3 from finite-temperature dynamical mean field theory

Thu, 14 May 2026 00:00:00 +0000

Li 2 MnO 3 is a key component of Li-excess layered cathodes of the form (1 − x ), LiMO 2 + x , Li 2 MnO 3 (M = Mn, Ni, Co, …), yet its role in setting Li-ion transport limitations remains under debate. Li 2 MnO 3 is a key component of Li-excess layered cathodes of the form (1 − x ), LiMO 2 + x , Li 2 MnO 3 (M = Mn, Ni, Co, …), yet its role in setting Li-ion transport limitations remains under debate. Here we combine DFT+U, finite-temperature DFT+DMFT with a continuous-time quantum Monte Carlo impurity solver, and nudged-elastic-band (NEB) calculations to study Li + migration in paramagnetic Li 2 MnO 3 in the presence of a single Li vacancy. Evaluating DMFT total energies along the DFT+U NEB geometries reveals that dynamical correlations strongly renormalize the lowest-barrier processes, reducing the activation energies to E a = 0.18 eV for the shortest-range hop and E a = 0.50 eV for the next-lowest (transport-controlling) step. The 0.18 eV barrier quantitatively reproduces...

Advanced pathways for hydrogen production: a collective view from a technical experts meeting

Thu, 14 May 2026 00:00:00 +0000

The current status of advanced water splitting pathways (using photoelectrochemical, biological and thermochemical platforms) toward viable technologies to produce renewable and sustainable hydrogen is assessed in a virtual international meeting. Hydrogen is an essential fuel and feedstock that can be produced in multiple ways to meet requirements for technological sectors that include energy storage, transportation, petroleum refining, and ammonia synthesis. To consider the future state of hydrogen manufacturing, a team of experts has assembled and examined three emerging hydrogen production technologies – photoelectrochemical, biological, and thermochemical. Each of these emerging technologies holds significant long-term potential for cost reduction while lowering industrial emissions associated with conventional methods of hydrogen manufacture ( e.g. , steam methane reforming) by using sunlight and renewable resources as primary sources of energy and feedstock, respectively....

Out-of-time-order correlators bridge classical transport and quantum dynamics

Thu, 14 May 2026 00:00:00 +0000

The out-of-time-order correlator (OTOC) has emerged as a central tool for quantifying decoherence across wide-ranging physical platforms. Here, we demonstrate its direct measurement in a classical ensemble using nuclear magnetic resonance with a modulated gradient spin echo sequence and extend the method into a multidimensional correlation to track exchange phenomena. Position is encoded through magnetic field gradients and momentum through the velocity autocorrelation function, enabling experimental access to OTOCs for proton motion confined within the self-similar lattice of the metal-organic framework MOF-808. Here, water confined to specified geometries within the MOF pores gives rise to spatially distinct diffusive eigenmodes with characteristic relative entropies. We demonstrate that periodic radio frequency driving combined with gradient modulation yields entropy evolution through the selection of distinct diffusion modes. Frequency-resolved diffusion spectra connect these...

Extended Rice–Thomson analysis and atomistic simulations revealing grain boundary effects on fracture in refractory high-entropy alloys

Thu, 14 May 2026 00:00:00 +0000

Understanding how grain boundaries mediate fracture remains a critical challenge in designing ductile, high-performance refractory alloys. Here, we extend the Rice-Thomson criterion to account for the angle between cracks and the impinging grain boundaries (GBs), capturing the competition between intergranular fracture and dislocation-mediated plasticity. Using machine learning interatomic potentials, we performed molecular statics simulations to probe fracture mechanisms in nanocrystalline NbMoTaW and Nb₄₅Ta₂₅Ti₁₅Hf₁₅, each with two different grain sizes, revealing trends consistent with experimental observations and the extended Rice model. Comparison with averaged R-curves for bulk samples demonstrates that GBs enhance ductility in Nb₄₅Ta₂₅Ti₁₅Hf₁₅ in both grain sizes investigated. In contrast, GBs only locally improve fracture resistance in NbMoTaW when cracks are temporarily pinned at...

Symmetry-Protected Moiré Band Engineering and Enhanced Electron–Phonon Coupling in Xe/Bi2Se3 Superlattices: Path to Topological Superconductivity

Thu, 14 May 2026 00:00:00 +0000

Observation of superconductivity, magnetism, and correlated insulating phases driven by the moiré potential in twisted graphene bilayer has opened the exciting new field of "twistronics". Even richer physics is expected if moiré superlattice could be generated on topological insulators; however, until now, experimental studies have been scarce. Here, we demonstrate topological moirés generated by adsorbing a monolayer of noble gas on a topological insulator. By angle-resolved photoemission spectroscopy, we show that the moiré potential replicates the topological surface state and affects it in a way fundamentally different from the trivial states. Replicated Dirac cones generally avoid crossings, except at the time-reversal invariant momenta that remain gapless. This creates van Hove singularities at the moiré Brillouin zone corners, providing the mechanism of enhancing correlations. Indeed, we observe a strong enhancement of the electron-phonon coupling strength that, if properly...

The Interplay of Pauli Repulsion, Electrostatics, and Field Inhomogeneity for Blueshifting and Redshifting Vibrational Probe Molecules

Thu, 14 May 2026 00:00:00 +0000

Many molecules' vibrational frequencies are sensitive to intermolecular electric fields, enabling them to probe the field in complex molecular environments. However, it is often unclear whether the probe is responding to the local electric field or other types of intermolecular interactions, inhibiting interpretation of the frequency and effectiveness as probes. This is especially true for molecules whose vibrational frequencies blueshift instead of the more typical redshift in hydrogen bonding configurations. Here, we computationally investigate the causes of redshifting versus blueshifting over a range of vibrational reporters. First, we apply adiabatic energy decomposition analysis to a paradigmatic set of probes, finding that redshifting only occurs when electrostatic interactions are strong enough to overcome the dominant and large blueshifting contribution of Pauli repulsion. Furthermore, we demonstrate that field inhomogeneity can further shift the frequency of many probes...

Improvements in optical metrology for high-performance variable-line-spacing x-ray gratings

Wed, 13 May 2026 00:00:00 +0000

We discuss a project to develop a precision metrology system for variable-line-spacing x-ray gratings using interferometric microscopes. We are developing test standards and calibration techniques to measure and correct for geometrical distortion and blur, and data processing techniques to combine multiple measurements and measure line spacing with high accuracy.

New Materials for Photoelectrochemical Energy Conversion

Wed, 13 May 2026 00:00:00 +0000

This review concerns light-to-chemical energy conversion, focusing on approaches that could be driven by terrestrial sunlight to produce hydrogen and/or reduce carbon dioxide. Recent advances in photocatalytic (PC) and photoelectrocatalytic (PEC) materials are covered. In both approaches, the electron-hole pairs that are created by photon absorption must travel in specific directions to the sites that mediate multielectron bond making/breaking redox reactions. Thermodynamic requirements for materials stability are described, although some recently discovered materials appear to be exceptions. For PC materials, the importance of rate matching between reduction and oxidation processes and the mass transfer of intermediates and products is emphasized. Surprisingly, metal sulfides appear to be promising for PC carbon dioxide reduction. For PEC materials, recent work elucidating the elementary step mechanism for oxygen evolution on metal oxides and the discovery of chalcogen-based...

Comparison of theory with the experimental characterization of the spatial frequency response of interferometers using a binary pseudo-random array sample

Wed, 13 May 2026 00:00:00 +0000

Experimental evaluations of the surface height response of an interference microscope using a binary pseudo-random array test sample are compared with a theory based on a Fourier optics model. Measurements of key instrument characteristics, including the illumination, imaging, and obscuring apertures of three different Mirau objectives, support the theoretical calculations. Agreement between experimental and theoretical modeling confirms the predictability of the spatial frequency response for the purpose of specification and optimization of instrument configuration for specific metrology tasks. The results also provide confidence in methods of compensating for the decrease in instrument response with spatial frequency.

Engineering micromotion in Floquet prethermalization via space-time symmetries

Tue, 12 May 2026 00:00:00 +0000

We present a systematic framework for Floquet prethermalization under strong resonant driving, emphasizing the pivotal role of dynamical space-time symmetries. Our approach demonstrates how dynamical space-time symmetries map onto the projective static symmetry group of the prethermal Hamiltonian governing the prethermal regime. We introduce techniques for detecting dynamical symmetries through the time evolution of local observables, facilitating a detailed analysis of micromotion within each period and surpassing the limitations of conventional stroboscopic Floquet prethermal dynamics. To implement this framework, we present a prethermal protocol that preserves order-2 dynamical symmetry in a spin-ladder model, confirming the predicted relationships between the expectation values of local observables at distinct temporal points in the Floquet cycle, linked by this symmetry.

A highly utilized and practical lithium-sulfur positive electrode enabled in all-solid-state batteries

Fri, 8 May 2026 00:00:00 +0000

All-solid-state batteries using sulfur-based positive electrodes (cathodes) offer a cost-effective route to achieve high specific energy. However, low active material utilization and cycle life hinder performance. Here, we demonstrate a positive electrode design that employs sulfide solid-state electrolytes, where a high energy synthesis approach forms a metastable and ionically conductive interphase on the active material surface. This interphase facilitates high active material utilization and contributes capacity with cycling. We also show that tailoring active material particle sizes to the micron-scale improves rate performance and cycling stability. Structural analysis reveals that the substantial volume change of sulfur-based positive electrodes during operation can partially offset that of the negative electrodes, thereby mitigating internal mechanical stress. The combined design principles enable sulfur areal capacities up to 11 mAh cm-2 while maintaining stable cycling...

Quantitative X‐ray scattering and reflectivity measurements of polymer thin films with 2D detectors

Thu, 7 May 2026 00:00:00 +0000

Abstract We describe a fully open‐sourced Python package to process raw X‐ray scattering data using a GANESHA SAXSLAB facility, and review in this manuscript the connection of X‐ray scattering theories with the open‐sourced package. This package affords researchers more flexibility in analyzing and visualizing X‐ray scattering and reflectivity data from what is now a commonplace facility at many universities and research laboratories engaged in polymer research. We briefly review the applications of X‐ray scattering and diffraction, followed by the scattering theories. A pedagogical introduction to processing X‐ray scattering data is provided using the modules in the Python package. We compare conventions to visualize and interpret transmission and grazing‐incidence scattering data using self‐assembled lamellar morphology of bottlebrush copolymers as an example, then describe how area detectors measure specular and off‐specular reflectivity. Examples of in‐house reflectivity and...

Bypassing the yellow phase for extremely stable formamidinium lead iodide perovskite solar cells.

Thu, 7 May 2026 00:00:00 +0000

Using modeling and structural studies, we show that chloride incorporation in formamidinium lead iodide (FAPI) perovskites alters the energetics of both the formation and degradation pathways. We fabricated films with two coadditives [15 mole % FA chloride (FACl) and 0.5 mole % BA₂PbI₄, where BA is butylammonium)], in which FACl ensures chloride incorporation and both additives collectively create a compressive lattice strain that stabilizes the FAPI black phase and bypasses the formation of a yellow phase during degradation. The coadditive strategy revealed a favorable transition from face-sharing 2H, 4H, 6H, and 8H phases to the corner-sharing 3C black phase. Photovoltaic devices with a p-i-n architecture had an average power conversion efficiency (40 devices) of 24.1% and lost only 2% of their efficiency after 1200 hours at 85° ± 5°C, 1-sun illumination, and open-circuit conditions. Upon stressing at 15-sun illumination at 90°C for >400 hours, the stabilized...

Absorption dissymmetry factor enhancement: A data-driven approach to unravel the synthesis knobs of chiral 2D perovskites

Thu, 7 May 2026 00:00:00 +0000

Chiral 2D metal halide perovskites (MHPs) are promising for spin-optoelectronic applications, yet their absorption dissymmetry factor (g abs ) exhibits significant variability due to complex, co-dependent structural and experimental factors. We established a data-driven framework using Pearson’s correlation, ANOVA, and Gaussian process regression to identify and model key synthesis “knobs” governing these properties. The analysis revealed that solvent choice is the primary factor driving variability. For acetonitrile-based films, g abs was maximized by optimizing annealing temperature and film thickness. Conversely, films from higher boiling point solvents showed complex dependencies on annealing temperature, excitonic integral intensity, and film texture. These statistical correlations provide a roadmap for the rational design of high-performance chiral MHPs and establish a foundation for future machine learning-driven material exploration.

Interfacial Inversion of Stealth Surfactants

Thu, 7 May 2026 00:00:00 +0000

Amphiphilic macromolecular surfactants segregate to liquid-liquid interfaces, thereby reducing the interfacial tension and free energy. We investigated "stealth surfactants" in the form of core-shell bottlebrush polymers comprised of pH-responsive diblock copolymer side chains forming a hydrophilic core and a hydrophobic shell, enabling solubility in oil. At liquid-liquid interfaces, these polymers undergo a structural "inversion", with hydrophilic blocks segregating into the aqueous phase and hydrophobic blocks residing in the oil phase. The reconfiguration kinetics and surfactant properties are influenced by multiple factors, including the molecular weights of the backbone and side chain components, the hydrophilic-to-hydrophobic balance of the side chains, and the pH of the aqueous phase. An observed nonmonotonic dependence of interfacial tension with time is attributed to a progressive structural inversion, where the projected area of the macromolecule onto the interface decreases....

hashin_shtrikman_mp: a package for the optimal design and discovery of multi-phase composite materials

Wed, 6 May 2026 00:00:00 +0000

hashin_shtrikman_mp: a package for the optimal design and discovery of multi-phase composite materials

The Transition From Melt Accumulation to Eruption Initiation Recorded by Orthopyroxene Fe‐Mg Diffusion Timescales in Late Holocene Rhyolites, South Sister Volcano, Oregon Cascade Range

Tue, 5 May 2026 00:00:00 +0000

Abstract South Sister volcano, Oregon Cascade Range, USA, has repeatedly erupted rhyolite since ca. 40 ka. The youngest such eruptions are the ca. 2 ka Rock Mesa and Devils Chain rhyolites, erupted several hundred years apart from two multi‐vent complexes separated by 3–6 km. Fe‐Mg interdiffusion models of orthopyroxene rims from both rhyolites produce timescales up to several‐thousand years, but dominantly decades‐to‐centuries. Notably, the timescales of step‐normal zoned orthopyroxene rims (i.e., normally zoned with a steep chemical gradient) from the Rock Mesa rhyolite are longer than those of reversely zoned crystals, whereas the Devils Chain produced mostly decadal timescales for both zoning types. Despite the proximity and broadly similar products of these episodes, their respective timescales indicate distinct sequences of events leading up to each eruption. The Rock Mesa timescales record centuries of magma chamber growth followed by decades of predominantly...

Wireless Bioelectronic Modulation of Membrane Potential in Glioblastoma Using Carbon Nanotube Porins

Tue, 5 May 2026 00:00:00 +0000

Disruption of membrane potential (V_mem) can activate pathways associated with cancer proliferation. Manipulating ion channels may therefore present an effective strategy for treating cancers that fail to respond to conventional therapies. One approach to target these channels is to manipulate the membrane charge, which involves the use of wireless bipolar electrodes such as carbon nanotube porins (CNTPs) inserted into cell membranes to modulate membrane charge and ionic flux. By utilizing membrane dyes, we observed alterations in V_mem induced by CNTPs and externally applied voltages. Analyses of cellular behaviors and processes indicated that V_mem is more receptive to stimuli in invasive cancers, while it leads to increased metabolism in less invasive cancers, with notable changes in the cell cycle occurring at approximately 48 h post-treatment in Glioblastoma (GB) cell lines. This work shows that CNTPs, in combination and with externally...

Patterned, Low-Temperature Growth of Transition Metal Dichalcogenides for Low Resistance Raised Contacts

Tue, 5 May 2026 00:00:00 +0000

Transition metal dichalcogenide (TMD) monolayers are promising channel materials for next-generation electronic devices. A challenge is the high contact resistance between monolayer TMDs and metal contacts, especially for holes. In this regard, raised source/drain contacts are promising. However, the direct, patterned growth of raised contacts at CMOS-compatible temperatures remains largely unresolved. We present plasma-free selenization and sulfurization of metal oxides at substrate temperatures down to 400 °C, compatible with back-end-of-line thermal budgets. To achieve growth at such temperatures, gas-phase chalcogen precursors are first thermally activated at 950 °C. Films grown on single-crystal monolayer TMDs exhibit high crystal quality, as confirmed by transmission electron microscopy. Raised contacts on WSe2 monolayers fabricated using this approach yield a low hole contact resistance of 0.3 kΩ·μm after chemical doping. This process is shown to be applicable to growing...

Front Matter: Volume 7969

Wed, 29 Apr 2026 00:00:00 +0000

This PDF file contains the front matter associated with SPIE Proceedings Volume 7969, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Navigating the research landscape for hyper-NA EUV lithography and future patterning technologies

Wed, 29 Apr 2026 00:00:00 +0000

Hyper-Numerical Aperture (Hyper-NA) Extreme Ultraviolet (EUV) lithography is gathering growing support as the technology of choice to sustain the dimensional scaling trajectory of Moore's Law. This transition, which targets resolution down to 5 nm, necessitates several research advances across several key lithography areas, such as patterning materials, imaging with polarization control, and the optimization of the mask structure. In this paper, we briefly review the historical role of the government-industrial partnerships enabling Center for X-Ray Optics (CXRO) pathfinding research for prior EUV lithography generations. We also highlight the role of the Department of Energy's Energy Frontier Research Center (EFRC) on High-Precision Patterning Science (CHiPPS) as a critical initiative to fundamentally address the pervasive stochastic challenges in materials science that limit the RLS (Resolution, Sensitivity, Line Edge Roughness) tradeoff, charting a path toward the Angstrom...

Highly Anisotropic Quasi‐Direct Organic Metal Halide Hybrids: A Platform for Polarization‐Sensitive Optoelectronics

Tue, 28 Apr 2026 00:00:00 +0000

ABSTRACT Low‐dimensional organic–inorganic metal halide hybrids (OMHHs) exhibit remarkable optical properties and enhanced environmental stability. We investigate a 1D OMHH with formula C 4 N 2 H 14 PbBr 4 , consisting of Pb–Br chains separated by organic cations, which shows a large Stokes shift (0.83 eV) and broadband emission. Through first‐principles calculations and polarized Raman spectroscopy, we characterize the material's vibrational properties and identify the specific phonon modes that drive exciton self‐trapping. Our novel GW/Bethe‐Salpeter equation force formalism reveals that low‐frequency phonons (100100 cm − 1 , primarily involving Pb–Br motions) couple strongly with excitons, with a remarkably high Huang‐Rhys factor of 137 ± 4, and gives a pathway for ultrafast structural analysis during the absorption process. This phonon‐exciton coupling mechanism explains the material's broadband emission and provides a pathway for controlling optical properties through...

Electronic Structure Tuning of Lanthanidocene Photocatalysts for C–F Bond Cleavage