Kory Burns1, Eva Zarkadoula2, Chris Smyth3, Jordan A. Hachtel2
1Department of Materials Science and Engineering, University of Virginia, USA
2Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, USA
3Sandia National Laboratories, Albuquerque, NM, USA
Two-dimensional (2D) compound semiconductors and dielectrics exhibit a range of levels of disorder dependent on their...
We present the development of a scanning fiber-based nitrogen-vacancy (NV) center microscope for magnetic imaging under ambient conditions. The system integrates a microdiamond containing a high density of NV centers affixed to the end of an optical fiber, enabling remote excitation and collection of NV fluorescence. The sample is mounted on a 3D nanopositioning stage below the fiber tip,...
Two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, possess unique physical and chemical properties, enabling diverse applications in fields ranging from energy storage to communication, catalysis, sensing, healthcare, and beyond. Despite extensive research and notable advancements, a fundamental understanding of MXenes’ phase diversity and its connection to their...
Neutron reflectometry is a powerful tool for interrogating the structure of thin films at interfaces. Surface-adsorbed lipid bilayers in liquid flow cells provide a platform for a wide range of biophysical measurements, from protein structures to antimicrobial peptide activity to interfacial forces. Lipid bilayers are chemically complex, with an enormous combinatorial space of compositions; as...
Strongly correlated quantum materials promise to revolutionize many energy-related technologies, but owing to their complexity, their discovery process is rather slow. This talk will discuss how AI can help speed up this process: By accelerating expensive computational simulations and facilitating the conversion of abstract numerical data into experimentally accessible observables, AI can...
Antifouling polymers are highly valuable in a variety of applications, including antiviral coatings, targeted drug delivery, and marine coatings, where preventing unwanted protein adsorption is critical. Although extensive experimental studies have characterized polymer-protein interactions, computational studies remain limited due to the difficulty and complexity of integrating and...
Atomic Force Microscopy (AFM) enables high-resolution imaging of material surfaces at the atomic scale, offering detailed insights into structural and functional properties. However, its limited scan area poses challenges in linking nanoscale features to macroscopic structures, particularly in applications like large-area composite analysis or dynamic change studies. To overcome this, it is...
Traditional approaches to bridge atomistic dynamics with experimental observations at the microstructural level often rely on phenomenological models of the underlying physics, whose free parameters are in turn fitted to a small number of intuition-driven atomic scale simulations under limited number of thermodynamical drivers (e.g., temperature, pressure, chemical potential etc). This tedious...
Mirror matter has been proposed as a potential explanation for dark matter, with neutron-mirror neutron ($n \leftrightarrow n^{\prime}$) oscillations providing a possible signature of its existence. To search for this effect, we conducted an experiment using a cold neutron beam and the GP-SANS instrument at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. The experiment...
At around 30 kb, the SARS-CoV-2 genome is one of the largest viral genomes among RNA viruses. As such, the replication machinery must be prepared to quickly and efficiently replicate this genome in order for the viral infection to effectively persist. The SARS-CoV-2 replication-transcription complex (RTC) involves several non-structural proteins encoded by the viral genome that accomplish this...
This abstract focuses on the recent work in developing the most promising PGM-free catalysts for electrochemical energy applications, which are closed collaborated with scientists at Oak Ridge National lab. In particular, single and dual atom catalysts based on atomically dispersed, nitrogen-coordinated metal sites (M–N–C catalysts) will be discussed in terms of their history, present...
Neutron reflectometry (NR) is a unique characterization technique for studying the structure of thin films due to its high spatial resolution, non-destructive nature, and the sensitivity of neutrons to both isotopes and spin. Machine Learning techniques, on the other hand, provide the opportunity to analyze large amount of data and predict outcomes. Here, we combine machine learning and NR...
Membrane proteins play crucial roles in many cellular processes, however, studying membrane proteins is challenging because of their complex structure and fragility when isolated from their native environment. One solution is to embed membrane proteins in a membrane-mimic to provide a more native environment to facilitate their characterization. Small-angle neutron scattering (SANS) is an...
Ferroelectric materials exhibit diverse behaviors influenced by local structure, domain configurations, and external stimuli. To support their systematic exploration, an integrated platform has been developed that combines autonomous scanning probe microscopy (SPM), physics-informed measurements, and machine learning-guided decision-making.
In one study, domain wall dynamics in PbTiO₃/KTaO₃...
Biofouling has widespread implications for everyday materials, including biomedical devices, personal protective equipment, and marine coatings, leading to performance degradation and high costs. Polyzwitterionic brush coatings are known to exhibit antifouling behavior due largely to a strongly coupled hydration layer, yet the detailed mechanism is not fully understood. Moreover, only a...
What to learn and predict is a question facing domain scientists when they would like to leverage the advances in machine learning to their specific areas of research. In this talk, I will discuss how my group is answering this question in my research interest of computational materials chemistry for nanocatalysis and energy storage. Through two case studies, I will show the power of deep...
Matthew T. McDowell
Professor and Carter N. Paden, Jr. Distinguished Chair
G. W. Woodruff School of Mechanical Engineering
School of Materials Science and Engineering
Georgia Institute of Technology, USA
The advent of lithium-ion batteries has brought about a revolution in portable energy storage, spurring the rapid growth of the electric vehicle market. However, further advances in...
Over the past 17 years, nearly 600 publications have explored microfluidic platforms or tissue chips for localized drug perfusion and electrophysiological monitoring of organotypic brain slices. However, only a few studies report actual axonal projections from these slices. Achieving axonal outgrowth in microfluidic systems has remained difficult and is often deemed infeasible in peer review....
This work details the development of a cell-on-CMOS biosensor system that integrates fully carbonized 3D-printed nanoelectrodes with CMOS readout circuits for real-time cellular monitoring. The electrodes were fabricated using a platinum-on-titanium metal stack, chosen for its superior adhesion and thermal stability. Electrode layouts were designed in the industry-standard GDSII format and...
Lithium-excess disordered rocksalt (DRX) materials are a promising class of Co- and Ni-free lithium-ion battery cathodes that offer high specific energy density (up to 1000 Wh kg$^{-1}$) and reversible capacity (up to 300 mAh g$^{-1}$). Compared to traditional Li-ion cathodes (e.g., LiNi$_x$Mn$_y$Co$_{1-x-y}$O$_2$), DRX oxides/oxyfluorides are compatible with a wider range of earth abundant...
The Experimental Steering for Powder Diffraction (ESPD) project aims to help develop and commission automation and steering neutron powder diffraction experiments. Recently, successful experiments on the Nanoscale-Ordered Materials Diffractometer (NOMAD) at the Spallation Neutron Source (SNS) were conducted for the ESPD project and results will be presented. Specifically, iron(III) oxide /...
Tanvi Sheth, Andrea Perez, Nairiti Sinha, David Zhao, Glenn Fredrickson, M. Scott Shell
and Matthew E. Helgeson
Department of Chemical Engineering, UC Santa Barbara
Surfactant mixtures and blends are ubiquitous in industrial practice – yet little is understood about the molecular interactions they experience at fluid interfaces, and how these interactions control interfacial properties. In...
Gallium is a prototypical liquid metal and has gained resurgent attention due to its unique properties. Its atomic dynamics remain elusive despite a large number of studies, mainly due to the challenges of quantifying the atomic-scale dynamics of liquids. Recent developments in inelastic neutron scattering enable us to measure the Van Hove correlation function that describes the real-space...
We provide experimental evidence for the absence of a magnetic moment in bulk RuO$_2$, a candidate altermagnetic material, by using a combination of inelastic neutron and X-ray scattering, Mössbauer spectroscopy, nuclear forward scattering, and density functional theory calculations. The lattice dynamics from our inelastic neutron/x-ray scattering experiments were compared to density...
Recent advances in understanding Berry curvature effects have shown that the topological properties and electronic band structure of noncentrosymmetric semimetals can be harnessed to achieve quantum-limit THz detection, overcoming traditional limitations through giant nonlinear optoelectronic and optical effects. These breakthroughs open new pathways for quantum THz sensing, light sources, and...
Building upon the Neutron Data Interpretation Platform (NDIP) and the Neutrons Open Visualization and Analysis (NOVA) framework developed at Oak Ridge National Laboratory (ORNL), we have developed a VTK-based interactive software tool, CT Scan Visualizer, for performing rapid visualization of data produced by imaging instruments such as VENUS at the Spallation Neutron Source (SNS).
This...
We report a new class of Cu-based chalcogenide nanocrystals, Cu₂ZnASₓSe₄₋ₓ, (A= Al, Ga, In), synthesized via a novel modified hot-injection route. The nanocrystals were experimentally characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis absorbance spectroscopy, and steady-state and time-resolved photoluminescence (PL). Analysis of XRD peak intensities...
Ion conduction in ceramic materials is crucial for the performance and reliability of various functional materials, such as gate dielectrics, electrochemical transistors, and memristors. In crystalline materials, ion conduction depends on point defects like vacancies and interstitials, making ionic conductivity directly proportional to defect concentration and mobility. However, in amorphous...
Designer van der Waals (vdW) materials offers enormous opportunities to tune material properties for various applications. Isolated, optically-active defects generated in vdW materials could lead to single photon emission. 2D vdW materials as host materials for single photon emission hold various advantages, such as high optical extraction efficiency from the atomically-thin layered materials,...
The bacterial cytoplasm is characterized by a distinctive membrane-less organelle, the nucleoid, which harbors chromosomal DNA. We investigate the effects of dynamic processes associated with transcription and translation on the structure of this organelle, using coarse-grained molecular dynamics (MD) simulations implemented through the LAMMPS package and its recently developed REACTER module....
Multifunctional polymer nanocomposites are increasingly being explored for next-generation flexible electronics and smart sensing and energy harvesting applications. In this study, we report the fabrication and morphological optimization of electrospun nanofibers based on the ferroelectric copolymer poly(vinylidene fluoride–trifluoroethylene) (PVDF-TrFE), doped with magnetic iron oxide (Fe₃O₄)...
Autonomous labs are transforming scientific discovery by combining experimental steering, AI at the edge, real-time data movement, and in-situ decision making. Recent advances in these individual domains have made autonomous labs possible; however, the next major challenge is to break down disciplinary silos and build integrated ecosystems that make autonomous science accessible, scalable, and...
Significant recent effort has been devoted in understanding the geometric aspects of condensed matter [1]. The marriage of topology and magnetism at disparate quantum interfaces, guided by polarized neutron reflectometry (PNR), constitutes an exciting arena for developing novel memory, logic and information technologies. We introduce quasi-two-dimensional (2D) magnetic transition metal...
Epitaxial strain in films grown on lattice-mismatched substrates plays a key role in tuning a wide range of physical and chemical properties of transition metal oxides (TMOs) through the modulation of oxygen vacancies. Strain has also shown potential for enhancing the thermoelectric (TE) properties of TMOs, enabling efficient heat-to-electricity conversion. Nevertheless, the effect of...
Non-volatile resistive switching has emerged as an important concept in the development of high-density information storage and computing. The recent discovery of NVRS in two-dimensional (2D) monolayer structures, such as hexagonal boron nitride (hBN), open a new avenue for ultrathin memory/computing devices. The switching mechanism in 2D monolayers, however, is not fully understood. It is...
Ferroelectricity in wurtzite-based crystals was observed in 2019 and immediately introduced exciting opportunities to explore and discover new structure-property relationships in novel formulation spaces, and to investigate new integration and device implementations given new process compatibilities. The seminal discovery of ferroelectric Al1-xScxN initiated this excitement and was followed by...
Neutron scattering is an established workhorse for detecting signatures of quantum spin liquids (QSLs) including fractionalized excitations. However, this depends on having accurate magnetic form factors to analyze signals. These are commonly treated in an isolated, isotropic ion approximation, but the local magnetic degrees of freedom in QSL candidate materials are $j_{eff}$=$\frac{1}{2}$...
We present a first-principles investigation of the frequency-dependent dielectric properties of halide double perovskites Cs₂HfCl₆ (CHC), Cs₂ZrCl₆ (CZC), and the mixed alloy Cs₂Hf₀.₅Zr₀.₅Cl₆ (CHZC). Using density functional theory (DFT) and density functional perturbation theory (DFPT), we evaluated both the electronic (ε∞) and ionic (ε_ionic) contributions to the dielectric response. While ε∞...
Photonic Crystal Light Sails can travel through space without fuel on board and sustain a slight but continuous laser-driven acceleration for an extended period. Numerical simulations have shown that a specific type of Anisotropic Photonic Crystal Slab with three different dielectric constant regions exhibits a complete Photonic Band Gap for a narrow frequency range and is transparent for the...
Neutron scattering is a powerful characterization technique for investigating the structure and dynamics of biomacromolecules, as well as their interactions. In particular, small-angle neutron scattering (SANS) enables the characterization of structural features across a wide range of length scales, from just a few nanometers to several hundred nanometers. Additionally, SANS offers unique...
The demand for high energy efficiency drives intense interest in thermal management technology. The active control of heat flow in materials can dramatically enhance device efficiency. Lattice vibrations are a major contributor to heat transfer in solids and controlling them through external stimuli is a key challenge for thermal management. However, altering phonons is difficult due to their...
Coordination polymers (CPs) are emerging functional inorganic-organic hybrid materials formed by the coordination bond between a metal ion or cluster and an organic linker. Phase Change Materials (PCMs) can undergo reversible transitions between an amorphous phase to one or more crystalline polymorphs through external heating. CP-PCMs, with distinct optical and electrical properties that...
Compositionally complex oxides (CCOs) are promising candidates for thermal barrier coatings (TBCs) due to their low thermal conductivities, which arise from enhanced phonon scattering caused by cation disorder[1]. Compositionally complex rare-earth (RE) zirconate defect-fluorites (RE₂Zr₂O₇) combine low thermal conductivity with high melting temperatures, making them attractive for...
This talk presents our progress in developing autonomous workflows that generate DFT data and fit both reactive and machine-learned force fields to guide the molecular beam epitaxial synthesis and characterization of the van der Waals–layered topological insulator Bi₂Se₃. I will introduce pyRMG, our Python package for high-throughput real-space multigrid (RMG) DFT calculations on Frontier, and...
Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794-2275
Carbon black (CB) and silica (SiO2) filled elastomers are known to be the most successful polymer nanocomposites (PNCs) in industry, where “bound rubber (BR)” (i.e., polymer chains that are physically or chemically adsorbed on the nanofiller surface) plays a critical role in...
Additive friction stir deposition (AFSD) is a rapidly developing additive manufacturing (AM) process which is derived from friction stir welding (FSW). Unlike fusion-based AM methods which involve melting, AFSD is a solid state process which relies on heat generated during plastic deformation, reaching 60-90% of the deposited material’s melting temperature. Solid state processes avoid...
The development of advanced optoelectronic devices critically depends on the precise control of electronic and optical properties in functional materials. Among wide band gap oxides, ceria (3.0 ~ 3.2 eV) is a promising candidate due to its potential due to its tunable band gap, high chemical and thermal stability, and favorable ionic and electronic conductivity enabled by oxygen vacancies....
Understanding bacterial adhesion on biomaterial surfaces is critical for developing anti-bacterial and/or anti-fouling surfaces. In this study, we investigate two clinically relevant bacterial strains—Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 49775—on titanium dioxide (TiO₂) nano structured and flat surfaces, and bare glass substrates. Our goal is to elucidate how nanoscale...
Polyzwitterions (PZ) and polyanions (PA) mixtures attract a surge of interest due to their broad applications. Here, employing molecular dynamical simulations and neutron scattering experiments, we investigate the structures and dynamics of poly(3-(2-vinyl-1-pyridiniumyl)-1-propane sulfonate) (P2VPPS) and sodium poly(styrene sulfonate) (NaPSS) solutions in dilute regimes. Both simulation and...
Indium Tin Oxide (ITO), a transparent conducting oxide, is used industrially as an electrode for usage in LEDs, computers/phone screens, and photovoltaic devices. Most ITO thin films are deposited using RF vacuum deposition. An alternative deposition method known as sol-gel deposition, has the benefit of device fabrication under atmospheric conditions and wastes less material than sputtering....
All solid-state batteries are a rapidly expanding field with complex formations of both the anode and cathode materials. Solid-state lithium sulfur batteries provide increased energy storage and improved safety. We investigate the composition and formation of the solid electrolyte interface (SEI) for pristine and cycled sulfur-based solid-state batteries. We compare two sulfide solid state...
Neutron reflectivity excels at elucidating structure of soft mater interfaces. Sample environments have previously been used to study soft matter interfaces at rest, in compression, and subject to non-uniform shear stress. This work showcases a new custom tribometer design for conducting in situ measurements of forces during dynamic compression and linear sliding motion coupled with neutron...
Plasmonics has profoundly improved our ability to confine light and energy to regions far below the diffraction limit. There is intense recent interest in utilizing infrared-active plasmonic materials to direct infrared energy at the nanoscale and to tailor the material properties via interaction with low-frequency phonons. Furthermore, when resonant in the IR plasmonic structures can couple...
Macromolecular topology provides an opportunity to engineer polymers that provide orthogonal control over rheological performance and mechanical stability in high-shear rate applications. In this work, we combine topology-controlled polymer chemistry with in situ neutron scattering measurements in a high-shear capillary device (capillary rheo-SANS) that can probe the rheology and...
Poly(lactic acid) (PLA) is a biodegradable polymer that is used widely in biomedical applications due to its sustainability and biocompatibility. Naloxone is an opioid antagonist that is efficacious in the emergency treatment of opioid overdoses. However, its effectiveness in overdose reversal is limited by its rapid metabolism and short half-life, which require repeated dosage. We have...
Realistic modeling of quantum materials with both interactions and disorder, while challenging, has been a fruitful endeavour in explaining and informing experiments in condensed matter physics. Disorder is not only ubiquitous, but has been shown to give rise to novel phenomena like localization, suppressed critical temperature and metal-insulator transition. Experimental investigations, which...
Vibronic states are frequently observed in neutron scattering when excited crystal electric field (CEF) levels and phonons are in the same energy range. Typically this coupling is modeled phenomenologically. Here we successfully model the phonon-CEF coupling from first principles using density functional theory and an electrostatic point charge model. We find we are able to account for the...
Block copolymers (BCPs) are polymeric analogs of surfactants that form three-dimensional, ordered structures in the bulk and in thin films. Ordering of BCPs thin films is important as nanostructured materials find application in diverse areas such as chip-based (bio)sensors, battery electrolytes, and optoelectronic devices. It is well-known that the organization and alignment of a microphase...
Artificial lattices of carbon monoxide (CO) molecules on Cu(111) surfaces serve as powerful platforms for probing topological quantum effects relevant to quantum information science (QIS). In this multiscale computational study, we integrate density functional theory (DFT) and density functional tight-binding (DFTB) to characterize the electronic properties of honeycomb and Kagome CO lattices....
Quantum Spin Liquids (QSLs) emerge in frustrated magnetic materials where spins remain disordered even at 0 K. The presence of quasi-particles, long-range entanglement, and topological order makes QSLs a promising material platform for building inherently fault-tolerant devices for the storage and processing of quantum information. Several recent reports have proposed schemes to test and...
Understanding the link between how porous lithium-ion battery (LIB) electrodes are manufactured and the structure-function relationships that determine their performance is critical to accelerating the development of emergent battery technologies with higher rate cycling and capacity. Porous electrodes are manufactured by suspending a mixture of micron-sized electrochemically active material,...
Silicon-based optical structures such as interferometers, ring resonators, and photonic crystals hold great promise as low-cost sensor elements in part due to their compatibility with both standard microelectronics processing and standard surface functionalization techniques. The sensitivity of silicon-based optical biosensors is derived from the level of interaction between light and the...
Neutron Scattering workflows are a core part of daily operations for SNS and HFIR scientists at Oak Ridge National Laboratory (ORNL). However, there can be challenges relating to the ease of access, use, and reproducibility of these workflows. We have developed the Neutron Data Interpretation Platform (NDIP) and the Neutrons Open Visualization and Analysis (NOVA) framework to tackle these...
Three working groups were formed and led by members of the neutron scattering user community with support from ORNL instrument scientists. The groups examined 1) the science enabled by the largest static magnetic fields, requiring fixed, dedicated installations, 2) the scientific opportunities from static magnetic field sample environments that can be moved between and operated on multiple...
Disordered hyperuniform (DH) materials represent an ‘exotic’ class of materials that is characterized by the suppression of long-wavelength fluctuations (like single crystals) and the absence of long-range order (like liquids or regular amorphous materials). The concurrence of these otherwise mutually exclusive structure characteristics holds opportunities for the fabrication of heterogeneous...
There is considerable interest in replacing perfluoroalkyl surfactants (PFAS) with more environmentally benign substitutes in a range of industrial and consumer applications. Since individual alkyl and silicone-based surfactants consistently underperform against PFAS,
mixtures of surfactants are being considered as potential substitutes. In many cases, property data are interpreted assuming...
A charge density wave (CDW) is a phase of matter characterized by a periodic modulation of valence electron density coupled to a lattice distortion. In 1979, Alan Heeger predicted that the CDW transition should be accompanied by a divergence in the dynamic charge susceptibility, but this effect has never been observed experimentally. In this talk I will present momentum-resolved inelastic...
In the condensed phase, water ice contains a well-ordered lattice of Oxygen atoms that hosts a disordered network of Hydrogen atoms. At ambient pressure, water ice (Ih phase) has a hexagonal crystal structure, reflected geometrically in the 6-fold symmetry of snowflakes. The transition from ice Ih to ice XI, the most stable phase, is expected to occur at time-scales of ~10,000 years. The...
Multi-mode interferometers (MMIs) are used as optical couplers in integrated photonic devices with applications in areas such as optical switching, astrophotonics and quantum information. We propose and demonstrate a one-by-one (1x1) MMI fabricated at the Oak Ridge Center for Nanophase Material Science (CNMS) using magnesium-doped thin-film lithium niobate on silicon oxide on silicon. This MMI...
Quasi-one-dimensional systems have garnered significant attention owing to the exotic properties they can host including superconductivity, charge density waves, topological spin excitations and more. Pressure-induced superconductivity has been realized in a new family of Mn-based Q1D materials, AMn6Bi5 (A = K, Rb, Cs, Na), with unique [Mn6Bi5]−1 double-walled columns. The smallest...
Neutron polarization analysis is a powerful technique for condensed matter research. It can separate magnetic and nuclear components, determine the detailed spin direction, and observe weak ferromagnetic component and spin chirality. PTAX/HB-1, installed at the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory, has a variety of polarized equipment, such as Helmholtz coils...
Spin defects in solid-state systems are powerful platforms for quantum sensing and quantum information storage due to their long coherence times and compatibility with scalable architectures. In this work, we present scanning probe microscopy utilizing the nitrogen vacancy (NV) center in diamond to locally detect and image spin-based quantum sensors at the nanoscale. Specifically, we study the...
2D monolayers and heterostructures have become central to nanoscience in recent years, offering promising applications in electronics, sensing, and future computing. Significant progress has been made in 2D materials bottom-up synthesis and subsequent processing, driven by the need for harnessing and exploring exciting functional properties. Techniques such as encapsulation, doping, and...
Pyrvinium is a fluorescent red cyanine dye, whose salts - pyrvinium chloride salt and pyrvinium pamoate (PP) - have been extensively researched in a wide range of conditions. It has been approved by the FDA as a treatment for pinworm infestations. The substance's anti-cancer potential has garnered increasing attention in recent years and first clinical trial on the use of PP to treat...
Quantum materials with strong electronic correlations lie at the heart of modern condensed matter physics, exhibiting rich phenomena such as unconventional superconductivity, Mott insulating behavior, and quantum criticality. Realistic modeling of these systems necessitates the inclusion of disorder, which plays a crucial role in driving metal-insulator transitions (MITs), inducing electron...
Understanding the microscopic dynamics of various constituents in energy materials is crucial for exploring the fundamental mechanisms of energy storage and plays a significant role in their applications within energy storage and conversion technologies. By acquiring molecular-level structural and dynamic information about electrodes and electrolytes, we can create new materials with enhanced...
The Center for Structural Molecular Biology (CSMB) at Oak Ridge National Laboratory (ORNL) is a national user facility funded to support and develop the user access and science research program of the Biological Small-Angle Neutron Scattering (Bio-SANS) instrument at the High Flux Isotope Reactor (HFIR) dedicated to the analysis of the structure, function and dynamics of complex biological...
The field of Artificial Intelligence (AI) is experiencing a period of rapid growth, bringing transformative changes to many scientific domains. This presentation will provide a brief overview of the evolution of AI, highlighting key milestones and their relevance to neutron scattering. We will review the progression of our work, from early applications of neural networks to more recent...
VERITAS (HB-1A) located in the thermal beam room at HFIR, recently completed a major upgrade to rebuild the entire instrument. The instrument utilizes a double-bounce pyrolytic graphite monochromator system and a pyrolytic graphite analyzer to produce an intense, clean beam at l = 2.38 Å with low background and an excellent signal-to-noise ratio. The upgrade resulted in a >4x signal gain and...
The presence of nanoplastics (NPs) in the environment represents a major challenge due to potential soil/water contamination, and the transport of toxic substances. Their relatively small size (1–1000 nm) and high surface reactivity results in a wide range of complex interactions with heavy metals, organic matter, and biological substances. Understanding these interactions involves...
Nanopores embedded within monolayer hexagonal boron nitride (h-BN) offer possibilities of creating atomically thin ceramic membranes with unique combinations of high permeance (atomic thinness), high selectivity (via molecular sieving), increased thermal stability, and superior chemical resistance. However, fabricating size-selective nanopores in monolayer h-BN via scalable top-down processes...
The structures of RNAs and RNA-containing complexes regulate many biological processes. Despite their functional importance, RNA:RNA complexes represent a small fraction of experimentally-determined structures. We employed a joint small-angle X-ray and neutron scattering (SAXS/SANS) approach to structurally interrogate conformational changes in a model RNA:RNA complex. Using a combination of...
Small-Angle X-ray Scattering (SAXS) and X-ray Reflectometry (XRR) are powerful characterization techniques available at the Center for Nanophase Materials Sciences (CNMS) and the Neutron Scattering Division (NSD) at Oak Ridge National Laboratory (ORNL), enabling detailed nanoscale structural analysis of a wide range of materials. SAXS provides quantitative insights into the size, shape, and...
The interplay between charge density wave (CDW) and spin density wave (SDW) orders in quantum materials play a crucial role in the determination of their electronic, structural, and magnetic properties. Kagome lattice materials provide a platform to study these complex interactions, owing to their exotic electronic structures, including Dirac cones, van Hove singularities, and flat bands. The...
EuAuSb is a layered Dirac semimetal which exhibits a variety of unusual transport
phenomena, including chiral magnetic and topological Hall e?ects. The topological Hall
e?ect in particular is seen only in the magnetically ordered phase, suggesting that
symmetry breaking due to magnetic order may be important for understanding electronic
behavior. We have therefore collected single-crystal...
We report the synthesis of deuterated ionizable lipid SM-102 (13 steps, 96% deuteration). Empty and RNA loaded lipid nanoparticles, composed of deuterated SM-102, 1,2-distearoyl-sn-glycero-3-phosphocholine, cholesterol, and 1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol-2000, are synthesized using a syringe pump and a microfluidic chip. The particle size, uniformity, and internal...
A comprehensive study of Ge1-xMnxCo2O4 (GMCO) system was conducted using neutron powder diffraction (NPD), x-ray diffraction (XRD), Scanning electron microscopy, magnetometry, and heat capacity measurements. Comparative analysis with GeCo2O4 (GCO) highlights the influence of Mn substitution on the crystal and magnetic structure at low temperature. Surprisingly, phase separation is observed in...
The urgent need for sustainable chemical synthesis and material innovation has accelerated research at the intersection of soft matter science, bio-derived nanostructures, and green chemistry. This presentation demonstrates ongoing research at Macromolecular Nanomaterials Group on sustainable soft matter systems that leverage biological feedstocks and enzymatic processes to advance circular...
Glioblastoma multiforme (GBM) is the most aggressive and lethal primary brain malignancy, characterized by diffuse infiltration, treatment resistance, and profound molecular heterogeneity. Despite intensive tri-modal therapy—surgery, radiation, and temozolomide—median survival remains just 15 months, underscoring the need for more predictive models and novel therapies. Bioluminescence imaging...
The molecular mechanism of how the two sister chromosomes segregate and partition to two daughter cells in bacteria is not yet understood. A recent theoretical model has proposed that out-of-equilibrium processes associated with ribosome-mRNA (polysome) dynamics significantly influence the segregation of the two chromosomes. Here, we investigate the role of ribosomal dynamics on nucleoid...
Catalysts can be described by three important aspects: activity, selectivity, and stability. Activity is the ability of a catalyst to convert reactants into products. Selectivity is the ratio of the desired product to the total amount of converted molecules. Stability is the ability of a catalyst to maintain activity with respect to time on stream (TOS, time since initial contact of reactant...
Sample environment and instrument staff members from ORNL Neutron Sciences along with the NIST/NSF CHRNS partnership have been working together to bring cutting edge measuring tools online. This effort, the NIST-ORNL Integrated Sample Environment, or NOISE, has started with a handful of equipment focused on soft matter research such as RheoSANS, Stop Flow and Autonomous Formulation. We would...
Typical one-standard-deviation measurement uncertainties in neutron and x-ray diffraction may often fail to account for the complexity of residual strain fields in additively manufactured components. In these methods, measured strains are collected at multiple orientations to describe an underlying strain tensor. However, when only a few measurements are used or the model is overly simplified,...
Local atomic structure often differs from the global average structure as measured with diffraction and yet the local structure has a profound impact on materials functionalities. This structure-function relationship applies in many materials classes, ranging from organics to Li-ion battery cathodes to oxide and halide perovskites. Accurately characterizing this local structure has proven...
Mohammad Samin Nur Chowdhury1, Diyu Yang2, Shimin Tang3, Singanallur V. Venkatakrishnan2, Hassina Z. Bilheux3, Gregery T. Buzzard1, and Charles A. Bouman1
1Purdue University, IN 47907, US
2Apple Inc., Cupertino, CA, USA
3Oak Ridge National Laboratory, TN 37830, USA
chowdh31@purdue.edu
Hyperspectral Neutron Computed Tomography (HSnCT) is an advanced imaging technique in which...
This presentation explores the quantum spin dynamics and magnetic exchange interactions in Mn-doped II–VI semiconductor nanostructures—specifically (Cd₁₋ₓMnₓSe)₁₃ nanoclusters and monolayer ZnSe(en)₀.₅—using both optical and neutron-based techniques. These hybrid materials exhibit rich spin-dependent phenomena, including giant Zeeman splitting, exciton–magnon coupling, and magnetic polaron...
Reduction and subsequent data analysis are the two fundamental steps to interpreting small angle neutron scattering data. At Bio-SANS, we have developed new analysis tools to streamline the data reduction and primary data analysis workflows. We have developed a new interactive, web-based analysis tool for solution scattering of biomolecules and extensible to soft matter polymer samples that...
Symmetries fundamentally govern the emergent collective behaviors in quantum materials. Beyond crystallographic symmetries, magnetic symmetries, which arising from ordered spin configurations, also play a critical role in determining physical properties. Probing the full symmetry landscape, including its evolution under external stimuli, is essential for understanding exotic phases and guiding...
Dense suspensions with high solid volume fractions (ϕ ≥ 0.5) are prevalent in nature and throughout industry. These highly loaded suspensions can exhibit complex rheological behaviors, including both shear thinning and subsequent thickening with increasing shear rate. Understanding the mechanisms behind these rheological behaviors can improve the design of materials systems to behave as...
Antifouling strategies aim to prevent the adhesion and growth of unwanted biological organisms, such as bacteria, algae, and proteins, on material surfaces. Polyzwitterions, a subclass of polyampholytes bearing both positive and negative charges on each monomer, have shown exceptional antifouling capabilities due to their strong hydration layers and high surface energy, which together form a...
Vibration Spectroscopy and Nanodiffraction of Multi-phase Boron Nitride Thin Films.
Nooreen Qureshi & Kory Burns
Department of Materials Science and Engineering, University of Virginia, USA
Epitaxial growth of cubic boron nitride (c-BN) thin films on diamond is a holy grail for high-power electronics as it can efficiently dissipate heat due to its high thermal conductivity....
