Electrocatalytically active titanium oxynitride (TiNO) thin films were fabricated on commercially available titanium metal plates using a pulsed laser deposition method for energy storage applications. The elemental composition and nature of bonding were analyzed using X-ray photoelectron spectroscopy (XPS) to reveal the reacting species and active sites responsible for the enhanced electrochemical performance of the TiNO electrodes. Symmetric supercapacitor devices were fabricated using two TiNO working electrodes separated by an ion-transporting layer to analyze their real-time performance. The galvanostatic charge–discharge studies on the symmetric cell have indicated that TiNO films deposited on the polycrystalline titanium plates at lower temperatures are superior to TiNO films deposited at higher temperatures in terms of storage characteristics. For example, TiNO films deposited at 300 °C exhibited the highest specific capacity of 69 mF/cm2 at 0.125 mA/cm2 with an energy density of 7.5 Wh/cm2. The performance of this supercapacitor (300 °C TiNO) device is also found to be ∼22% better compared to that of a 500 °C TiNO supercapacitor with a capacitance retention ability of 90% after 1000 cycles. The difference in the electrochemical storage and capacitance properties is attributed to the reduced leaching away of oxygen from the TiNO films by the Ti plate at lower deposition temperatures, leading to higher oxygen content in the TiNO films and, consequently, a high redox activity at the electrode/electrolyte interface.
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Abstract Free, publicly-accessible full text available February 1, 2026 -
Abstract Stabilization of topological spin textures in layered magnets has the potential to drive the development of advanced low-dimensional spintronics devices. However, achieving reliable and flexible manipulation of the topological spin textures beyond skyrmion in a two-dimensional magnet system remains challenging. Here, we demonstrate the introduction of magnetic iron atoms between the van der Waals gap of a layered magnet, Fe3GaTe2, to modify local anisotropic magnetic interactions. Consequently, we present direct observations of the order-disorder skyrmion lattices transition. In addition, non-trivial topological solitons, such as skyrmioniums and skyrmion bags, are realized at room temperature. Our work highlights the influence of random spin control of non-trivial topological spin textures.
Free, publicly-accessible full text available December 1, 2025 -
Abstract Optical microcomb underpins a wide range of applications from communication, metrology, to sensing. Although extensively explored in recent years, challenges remain in key aspects of microcomb such as complex soliton initialization, low power efficiency, and limited comb reconfigurability. Here we present an on-chip microcomb laser to address these key challenges. Realized with integration between III and V gain chip and a thin-film lithium niobate (TFLN) photonic integrated circuit (PIC), the laser directly emits mode-locked microcomb on demand with robust turnkey operation inherently built in, with individual comb linewidth down to 600 Hz, whole-comb frequency tuning rate exceeding 2.4 × 1017 Hz/s, and 100% utilization of optical power fully contributing to comb generation. The demonstrated approach unifies architecture and operation simplicity, electro-optic reconfigurability, high-speed tunability, and multifunctional capability enabled by TFLN PIC, opening up a great avenue towards on-demand generation of mode-locked microcomb that is of great potential for broad applications.
Free, publicly-accessible full text available December 1, 2025 -
Abstract Explosive volcanic eruptions produce vast quantities of silicate ash, whose surfaces are subsequently altered during atmospheric transit. These altered surfaces mediate environmental interactions, including atmospheric ice nucleation, and toxic effects in biota. A lack of knowledge of the initial, pre-altered ash surface has required previous studies to assume that the ash surface composition created during magmatic fragmentation is equivalent to the bulk particle assemblage. Here we examine ash particles generated by controlled fragmentation of andesite and find that fragmentation generates ash particles with substantial differences in surface chemistry. We attribute this disparity to observations of nanoscale melt heterogeneities, in which Fe-rich nanophases in the magmatic melt deflect and blunt fractures, thereby focusing fracture propagation within aureoles of single-phase melt formed during diffusion-limited growth of crystals. In this manner, we argue that commonly observed pre-eruptive microtextures caused by disequilibrium crystallisation and/or melt unmixing can modify fracture propagation and generate primary discrepancies in ash surface chemistry, an essential consideration for understanding the cascading consequences of reactive ash surfaces in various environments.
Free, publicly-accessible full text available December 1, 2025 -
Abstract Existing pathways to produce graphite which include extraction of natural graphite impact the environment, while the conversion of fossil-driven carbon to graphite around temperatures as high as 3000 °C consumes large quantities of energy. Potassium - catalyzed graphitization is a more sustainable route and can achieve graphitic carbon formation at temperatures lower than 1000 °C, while enhancing pore formation and creating porous graphitic carbon (PGC). This two-step approach involves carbonization followed by graphitization. However, the compositions of the gaseous products have not been reported in prior studies. In this perspective, the chemical transformations underlying Alkaline Thermal Graphitization (ATG) for the co-production of synthesis gas (H2and CO) and PGC in a single step, utilizing lignocellulosic biomass, are reported. The presence of graphitic and porous carbon structures in PGC are well suited for supercapacitor applications. This promising approach maximizes resource recovery by upgrading volatile matter to synthesis gas and low value biomass residues to porous graphitic carbon (PGC), thus co-producing sustainable fuels and energy storage materials, while lowering CO2emissions compared to existing pathways to produce graphite.
Free, publicly-accessible full text available December 1, 2025 -
Abstract Oxide heterostructures exhibit a vast variety of unique physical properties. Examples are unconventional superconductivity in layered nickelates and topological polar order in (PbTiO3)n/(SrTiO3)nsuperlattices. Although it is clear that variations in oxygen content are crucial for the electronic correlation phenomena in oxides, it remains a major challenge to quantify their impact. Here, we measure the chemical composition in multiferroic (LuFeO3)9/(LuFe2O4)1superlattices, mapping correlations between the distribution of oxygen vacancies and the electric and magnetic properties. Using atom probe tomography, we observe oxygen vacancies arranging in a layered three-dimensional structure with a local density on the order of 1014 cm−2, congruent with the formula-unit-thick ferrimagnetic LuFe2O4layers. The vacancy order is promoted by the locally reduced formation energy and plays a key role in stabilizing the ferroelectric domains and ferrimagnetism in the LuFeO3and LuFe2O4layers, respectively. The results demonstrate pronounced interactions between oxygen vacancies and the multiferroic order in this system and establish an approach for quantifying the oxygen defects with atomic-scale precision in 3D, giving new opportunities for deterministic defect-enabled property control in oxide heterostructures.
Free, publicly-accessible full text available December 1, 2025 -
Abstract Intra‐articular injections of hyaluronic acid (HA) are the cornerstone of osteoarthritis (OA) treatments. However, the mechanism of action and efficacy of HA viscosupplementation are debated. As such, there has been recent interest in developing synthetic viscosupplements. Recently, a synthetic 4 wt% polyacrylamide (pAAm) hydrogel was shown to effectively lubricate and bind to the surface of cartilage in vitro. However, its ability to localize to cartilage and alter the tribological properties of the tissue in a live articulating large animal joint is not known. The goal of this study was to quantify the distribution and extent of localization of pAAm in the equine metacarpophalangeal or metatarsophalangeal joint (fetlock joint), and determine whether preferential localization of pAAm influences the tribological properties of the tissue. An established planar fluorescence imaging technique was used to visualize and quantify the distribution of fluorescently labeled pAAm within the joint. While the pAAm hydrogel was present on all surfaces, it was not uniformly distributed, with more material present near the site of the injection. The lubricating ability of the cartilage in the joint was then assessed using a custom tribometer across two orders of magnitude of sliding speed in healthy synovial fluid. Cartilage regions with a greater coverage of pAAm, that is, higher fluorescent intensities, exhibited friction coefficients nearly 2‐fold lower than regions with lesser pAAm (
R rm = −0.59,p < 0.001). Collectively, the findings from this study indicate that intra‐articular viscosupplement injections are not evenly distributed inside a joint, and the tribological outcomes of these materials is strongly determined by the ability of the material to localize to the articulating surfaces in the joint.Free, publicly-accessible full text available December 1, 2025 -
Abstract A key open question in the study of layered superconducting nickelate films is the role that hydrogen incorporation into the lattice plays in the appearance of the superconducting state. Due to the challenges of stabilizing highly crystalline square planar nickelate films, films are prepared by the deposition of a more stable parent compound which is then transformed into the target phase
via a topotactic reaction with a strongly reducing agent such as CaH2. Recent studies, both experimental and theoretical, have introduced the possibility that the incorporation of hydrogen from the reducing agent into the nickelate lattice may be critical for the superconductivity. In this work, we use secondary ion mass spectrometry to examine superconducting La1−x X x NiO2/ SrTiO3(X = Ca and Sr) and Nd6Ni5O12/ NdGaO3films, along with non-superconducting NdNiO2/ SrTiO3and (Nd,Sr)NiO2/ SrTiO3. We find no evidence for extensive hydrogen incorporation across a broad range of samples, including both superconducting and non-superconducting films. Theoretical calculations indicate that hydrogen incorporation is broadly energetically unfavorable in these systems, supporting our conclusion that extensive hydrogen incorporation is not generally required to achieve a superconducting state in layered square-planar nickelates.Free, publicly-accessible full text available December 1, 2025 -
Abstract Transparent oxide thin film transistors (TFTs) are an important ingredient of transparent electronics. Their fabrication at the back‐end‐of‐line (BEOL) opens the door to novel strategies to more closely integrate logic with memory for data‐intensive computing architectures that overcome the scaling challenges of today's integrated circuits. A recently developed variant of molecular‐beam epitaxy (MBE) called suboxide MBE (S‐MBE) is demonstrated to be capable of growing epitaxial In2O3at BEOL temperatures with unmatched crystal quality. The fullwidth at halfmaximum of the rocking curve is 0.015° and, thus, ≈5x narrower than any reports at any temperature to date and limited by the substrate quality. The key to achieving these results is the provision of an In2O beam by S‐MBE, which enables growth in adsorption control and is kinetically favorable. To benchmark this deposition method for TFTs, rudimentary devices were fabricated.
Free, publicly-accessible full text available September 11, 2025 -
Abstract The poor thermal stability of lactoferrin (LF) hinders its bioavailability and use in commercial food products. To preserve LF from thermal denaturation, complexation with other biopolymers has been studied. Here we present the complex formation conditions, structural stability, and functional protection of LF by α‐lactalbumin (α‐LA). The formation of the LF–α‐LA complexes was dependent on pH, mass ratio, and ionic strength. Changing the formation conditions and cross‐linking by transglutaminase impacted the turbidity, particle size, and zeta‐potential of the resulting complexes. Electrophoresis, Fourier‐transform infrared spectroscopy, and circular dichroism measurements suggest that the secondary structure of LF in the LF–α‐LA complex was maintained after complexation and subsequent thermal treatments. At pH 7, the LF–α‐LA complex protected LF from thermal aggregation and denaturation, and the LF retained its functional and structural properties, including antibacterial capacity of LF after thermal treatments. The improved thermal stability and functional properties of LF in the LF–α‐LA complex are of interest to the food industry.
Free, publicly-accessible full text available September 1, 2025