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This study introduces a novel approach to address the limitations observed in existing random number generator (RNG) designs, focusing on the resolution for insufficiently covered problem statements and study purposes. In response to these challenges, we propose a high-throughput metastable-based RNG tailored for cryptography applications. Our design is featured with a two-layer transient effect ring oscillator (TERO) architecture, meticulously crafted to mitigate the locking phenomenon and enhance RNG randomness. Leveraging interleaved two-layer TEROs, realised through NAND and NOR SR latches, our RNG achieves unpredictable irregular sampling, crucial for cryptographic applications. To further enhance irregular sampling, the first layer of the RNG employs a multiplexer that selects inputs randomly. This multiplexer is governed by selection signals generated by the second layer of the RNG, ensuring superior randomness. Implemented using TSMC 40-nm CMOS process, our RNG passed the FIPS 140–1 randomness test at a clock frequency of 100 MHz, boasting a remarkable throughput of 50 Mbps. This study represents a significant advancement in RNG technology, addressing previous shortcomings and paving the way for high-speed communication systems' secure cryptographic applications. [ABSTRACT FROM AUTHOR]

Mn2+-doped β-Zn2SiO4, a metastable phase of zinc silicate, is widely acknowledged for the uncertainties linked to its crystal structure and challenging synthesis process along with its distinctive yellowish luminescence. In this study, a vivid yellow luminescence originating from Mn2+-doped metastable zinc silicate (BZSM) nanophosphor is suggested, achieved through a straightforward single-step annealing process. The reliable production of this phosphor necessitates substantial doping, surplus SiO2, a brief annealing duration, and prompt cooling. The verification of the phase is demonstrated based on its optical and crystallographic characteristics. Moreover, the effective utilization of excimer lamps in practical scenarios is effectively demonstrated as a result of the vacuum ultraviolet excitation property of BZSM nanophosphor. This outcome paves the way for additional deployment of metastable zinc silicate in various fields, consequently generating novel prospects for future advancements. [ABSTRACT FROM AUTHOR]

Supersaturated alloys can exhibit superior properties and electrodeposition is a cost-effective and versatile technique to produce them. In this review, the chemical, mechanical and structural properties of supersaturated alloys are discussed, and connections with metallic glasses and high entropy alloys are also exposed. After discussing mechanisms causing supersaturation in electrodeposited alloys, an overview of the most important electrodeposited metastable alloys is provided, showing that they are mainly used as protective coatings able to improve corrosion resistance and tribological performance of a large variety of industrial components. Composition of the electrolytic baths and deposition parameters are also considered and discussed. [ABSTRACT FROM AUTHOR]

It has been observed by many authors that highly active electrocatalysts are frequently "disordered" or "amorphous" in nature. The correlation between this lack of order and functionality is highly debated, with researchers still questioning if this structural property is a simple coincidence of the material preparation method, or if this lack of order has an important functional role for these catalysts. Using metal oxides as an example, how amorphous and disordered metal oxides can react by fundamentally different pathways are explored from more ordered forms with very similar bonding and redox states. The distinction between amorphous, disordered, and crystalline materials is reviewed in different characterization methods and suggests how these material characteristics fundamentally change the reactivity of these materials beyond surface area effects. How disorder can change the underlying thermodynamic stability of a material is explored, which in turn impacts redox potential, proton‐transfer, and electron‐transfer properties. It is these fundamental properties that govern the electrocatalytic activity and microbial metabolism of these materials. It is further argued that understanding the amorphous and disordered state of materials may be key to understanding a range of catalytic reactions; from clean energy reactions to the biological systems that underpin life's existence. [ABSTRACT FROM AUTHOR]

Acid acts as a "fuel" in driving kinetic self‐assembly, with crystals of the CuII complex ([CuIICl2(BH)2], BH=benzothiadiazole helicene derivative) being successfully converted to crystals of 1 ([H2BH][CuBr3]) and 2 ([H2BH][CuBr3⋅2H2O]). The metastable features of 1 and 2 enable CuI guest release, with transformation into a thermodynamically favorable form 3 (H2BH⋅2Br). Compound 1 exhibits dual phosphorescence at 452 nm (3MC) and 709 nm (3CT) at room temperature. At lower temperatures, the 3CT band disappears and the 3MC band weakens, while a new emission band at 621 nm (3ππ*) is enhanced. In 1, the subtle structural change and significant emission change depending on temperature is reversible. In contrast, 2 exhibits only 3MC emission at room temperature, with less efficient triplet‐triplet energy transfer (TTET) below 250 K, and with residual 3ππ* emission occurring upon returning to room temperature, even after one week. [ABSTRACT FROM AUTHOR]

Conventional book casting of Sm2TM17-type alloys (where TM = Co, Fe, Cu, Zr) leads to a coarse, highly segregated microstructure, predominantly due to the slow, variable cooling rate from the mould surface towards the centre of the ingot. These cast alloys require a long homogenisation treatment to remove this segregation and develop a super-saturated, metastable SmTM7-type hexagonal phase. This SmTM7 phase is a vital precursor phase required during magnet production to develop the complex cellular structure responsible for high magnetic properties. In this work, strip casting was employed to facilitate rapid solidification to develop thin flakes (<0.5 mm thick) with a columnar grain structure. Rapid cooling has the potential to produce a homogenous microstructure consisting predominantly of the metastable SmTM7 phase. This could remove or significantly reduce the need for the energy-intensive homogenisation treatment usually required in conventional magnet manufacture. This paper investigates the effect of wheel speed (and hence cooling rate) on flake thickness, microstructure, and phase balance of the cast alloys. It was shown that for wheel speeds between 1.1 and 3.0 m/s, the microstructure showed large variation; however, in all cases, evidence of the columnar SmTM7 phase was presented. The adhesion between the melt and the wheel was deemed to be critical for the nucleation and subsequent columnar growth of SmTM7 grains, where the wheel speed controlled both the flow of the alloy onto the wheel and the thickness of the resultant flake. It was determined that in order to achieve a homogenous columnar SmTM7 structure, the maximum flake thickness should be limited to 270 μm to avoid the formation of equiaxed Sm2TM17 grains through insufficient cooling. [ABSTRACT FROM AUTHOR]

Phase modulation of noble metal alloys (NMAs) is critically important in nanoscience since the distinct atomic arrangements can largely determine their physicochemical properties. However, the precise modulation of NMAs is formidably challenging, because thermodynamically stable phases are generally preferential compared to those metastable ones. Herein, we proposed a potential energy trapping strategy for phase modulation of Pd-Te alloys with solvents. Thereinto, ethylene glycol can increase the energy barrier for both Pd leaching and Te introduction, forming metastable Pd20Te7 phase. Inversely, N, N-dimethylformamide is unable to trap metastable phase, inducing the phase evolution to thermodynamically stable PdTe phase, and the precise phase modulation was realized including Pd20Te7, PdTe and PdTe2 phases. The Pd-Te alloys displayed phase-dependent formic acid oxidation catalytic performance with PdTe phase showing the best. This work proposes a strategy for creating metastable phase with potential energy trap, which may deepen the understanding of phase engineering for noble metal-based nanocrystals. [ABSTRACT FROM AUTHOR]

Membraneless organelles (MLOs) are likely assembled via liquid–liquid phase separation (LLPS). The liquid‐like MLOs afford multifold peculiarities including high dynamics, reversibility and responsiveness. It is common to see fast, drastic, and reversible formation and dissolution events of MLOs, as well as transition into more stable glassy or gel‐like states, which suggests a metastable assembly state. Moreover, the alteration of metastability of LLPS is linked with cellular pathology. Here, we review the "metastability" related to MLOs driven by liquid phase separation, from multifaceted regards including energy state, molecular interactions, molecular structure, phase transition, as well as the associations with diseases. This review can help to advance the insight into properties and pathogenesis associated with LLPS of biological matter. Key points: Liquid–liquid phase separation emerges as a universal tool for the intracellular biomolecule organization, particularly via the formation of membraneless organelles.The liquid‐like membraneless organelles afford unique properties and have aroused wide interests among cell biologists.Metastability is a general feature of liquid‐like membraneless organelles, which has manifested in multiple aspects including energy state, molecular interactions, molecular structures, biological assemblages and its association with diseases.Understanding of metastability of biological liquid phase separation can not only help to elucidate the formation and properties of membraneless organelles, but also pave the way to the insight into pathogenesis. [ABSTRACT FROM AUTHOR]

We examine halide anion-exchange reactions on CsPbX3 nanorods (NRs), and we identify reaction conditions that provide complete anion exchange while retaining both the highly quantum-confined 1-D morphology and metastable crystal lattice configurations that span a range between tetragonal structures and thermodynamically preferred orthorhombic structures. We find that the chemical stability of CsPbBr3 NRs is degraded by the presence of alkyl amines that etch CsPbBr3 and result in the formation of Cs4PbBr6 and 2-D bromoplumbates. Our study outlines strategies for maintaining metastable states of the soft lattices of perovskite nanocrystals undergoing exchange reactions, despite the thermodynamic driving force toward more stable lattice configurations during this disruptive chemical transformation. These strategies can be used to fine-tune the band gap of LHP-based nanostructures while preserving structure–property relationships that are contingent on metastable shapes and crystal configurations, aiding optoelectronic applications of these materials. [ABSTRACT FROM AUTHOR]

Abstract Background 177Lu-radiopharmaceuticals can contain the metastable impurity [177mLu]lutetium with a physical half-life of 160.4 days, in varying concentrations depending on the route of production of the radionuclidic precursor [177Lu]lutetium. Due to the long half-life of [177mLu]lutetium, difficulties with waste disposal or sterility testing could arise. Here, we analyzed several 177Lu-samples of different origins and suppliers regarding their 177mLu-concentration. Results All samples tested showed a 177mLu-concentration in the range that was stated on the certificate of analysis from the supplier which is in accordance with the European Pharmacopoeia. Conclusions Although all 177mLu-concentrations were in accordance with the European Pharmacopoeia, we need to take into account the respective national legislation regarding radioactivity release limits. With regard to the German legislation, several probes for sterility testing in external laboratories could not be released for transport due to the concentration of [177mLu]lutetium. Moreover, waste water tanks should specifically be monitored for 177mLu-concentration, when e.g. Lutathera® is administered in the clinic.

Supersaturated alloys can exhibit superior properties and electrodeposition is a cost-effective and versatile technique to produce them. In this review, the chemical, mechanical and structural properties of supersaturated alloys are discussed, and connections with metallic glasses and high entropy alloys are also exposed. After discussing mechanisms causing supersaturation in electrodeposited alloys, an overview of the most important electrodeposited metastable alloys is provided, showing that they are mainly used as protective coatings able to improve corrosion resistance and tribological performance of a large variety of industrial components. Composition of the electrolytic baths and deposition parameters are also considered and discussed.

As compressed hydrides constantly refresh the records of superconducting critical temperatures (Tc) in the vicinity of room temperature, this further reinforces the confidence to find more high-temperature superconducting hydrides. In this process, metastable phases of superhydrides offer enough possibilities to access superior superconducting properties. Here we report a metastable hexagonal lanthanum superhydride (P 63 /mmc -LaH10) stabilized at 146 GPa by introducing an appropriate proportion of Al, which exhibits high-temperature superconductivity with Tc ∼ 178 K, and this value is enhanced to a maximum Tc ∼ 223 K at 164 GPa. A huge upper critical magnetic field value Hc2(0) reaches 223 T at 146 GPa. The small volume expansion of P 63 /mmc -(La, Al) H10 compared with the binary LaH10 indicates the possible interstitial sites of Al atoms filling into the La–H lattice, instead of forming conventional ternary alloy-based superhydrides. This work provides a new strategy for metastable high-temperature superconductors through the multiple-element system. [ABSTRACT FROM AUTHOR]

Supramolecular peptide assemblies have been widely used for the development of biomedical, catalytical, and optical materials with chiral nanostructures in view of the intrinsic chirality of peptides. However, the assembly pathway and chiral transformation behavior of various peptides remain largely elusive especially for the transient assemblies under out‐of‐equilibrium conditions. Herein, the N‐fluorenylmethoxycarbonyl‐protected phenylalanine‐tyrosine dipeptide (Fmoc‐FY) was used as a peptide assembly platform, which showed that the assembly proceeds multistep evolution. The original spheres caused by liquid‐liquid phase separation (LLPS) can nucleate and elongate into the formation of right‐handed helices which were metastable and easily converted into microribbons. Interestingly, a bipyridine derivative can be introduced to effectively control the assembly pathway and induce the formation of thermodynamically stable right‐handed or left‐handed helices at different stoichiometric ratios. In addition, the chiral assembly can also be regulated by ultrasound or enzyme catalysis. This minimalistic system not only broadens the nucleation‐elongation mechanisms of protein aggregates but also promotes the controllable design and development of chiral biomaterials. [ABSTRACT FROM AUTHOR]

Titanium-rich metastable medium-entropy alloys, designed for low elastic moduli, sacrifice strength. However, enhancing their mechanical strength is crucial for bio-implant applications. This study aims to enhance the mechanical properties and corrosion resistance of a metastable Ti80–Nb10–Mo5–Sn5 medium-entropy alloy using various treatments, including cold rolling (at 50% and 75% reduction) and precipitation hardening (at room temperature, 150 °C, 350 °C, 550 °C, and 750 °C). The results showed that the alloy underwent a stress-induced martensitic transformation during the rolling process. Notably, the α phase was precipitated in the β grain boundaries after 30 days of precipitation hardening at room temperature. The yield strengths of the alloy increased by 51% and 281.9% after room-temperature precipitation and 75% cold rolling, respectively. In potentiodynamic corrosion tests conducted in phosphate-buffered saline solution, the pitting potentials of the alloy treated using various conditions were higher than 1.8 V, and no pitting holes were observed on the surface of the alloys. The surface oxide layer of the alloy was primarily composed of TiO2, Nb2O5, MoO3, and SnO2, contributing to the alloy's exceptional corrosion and pitting resistance. The 75% rolled Ti80–Nb10–Mo5–Sn5 demonstrates exceptional mechanical properties and high corrosion resistance, positioning it as a promising bio-implant candidate. [ABSTRACT FROM AUTHOR]

Background: 177Lu-radiopharmaceuticals can contain the metastable impurity [177mLu]lutetium with a physical half-life of 160.4 days, in varying concentrations depending on the route of production of the radionuclidic precursor [177Lu]lutetium. Due to the long half-life of [177mLu]lutetium, difficulties with waste disposal or sterility testing could arise. Here, we analyzed several 177Lu-samples of different origins and suppliers regarding their 177mLu-concentration. Results: All samples tested showed a 177mLu-concentration in the range that was stated on the certificate of analysis from the supplier which is in accordance with the European Pharmacopoeia. Conclusions: Although all 177mLu-concentrations were in accordance with the European Pharmacopoeia, we need to take into account the respective national legislation regarding radioactivity release limits. With regard to the German legislation, several probes for sterility testing in external laboratories could not be released for transport due to the concentration of [177mLu]lutetium. Moreover, waste water tanks should specifically be monitored for 177mLu-concentration, when e.g. Lutathera® is administered in the clinic. [ABSTRACT FROM AUTHOR]

β-Ti alloys have long been investigated and applied in the biomedical field due to their exceptional mechanical properties, ductility, and corrosion resistance. Metastable β-Ti alloys have garnered interest in the realm of biomaterials owing to their notably low elastic modulus. Nevertheless, the inherent correlation between a low elastic modulus and relatively reduced strength persists, even in the case of metastable β-Ti alloys. Enhancing the strength of alloys contributes to improving their fatigue resistance, thereby preventing an implant material from failure in clinical usage. Recently, a series of biomedical high-entropy and medium-entropy alloys, composed of biocompatible elements such as Ti, Zr, Nb, Ta, and Mo, have been developed. Leveraging the contributions of the four core effects of high-entropy alloys, both biomedical high-entropy and medium-entropy alloys exhibit excellent mechanical strength, corrosion resistance, and biocompatibility, albeit accompanied by an elevated elastic modulus. To satisfy the demands of biomedical implants, researchers have sought to synthesize the strengths of high-entropy alloys and metastable β-Ti alloys, culminating in the development of metastable high-entropy/medium-entropy alloys that manifest both high strength and a low elastic modulus. Consequently, the design principles for new-generation biomedical medium-entropy alloys and conventional metastable β-Ti alloys can be converged. This review focuses on the design from β-Ti alloys to the novel metastable medium-entropy alloys for biomedical applications. [ABSTRACT FROM AUTHOR]

We present the stabilization of halide-terminated Ge nanoparticles prepared via a disproportionation reaction of metastable Ge(I)X solutions with well-defined size distribution. Further tailoring of the stability of the Ge nanoparticles was achieved using variations in the substituent. Ge nanoparticles obtained in this way are readily dispersed in organic solvents, long-term colloidally stable, and are perfect prerequisites for thin-film preparation. This gives these nanomaterials a future in surface-dependent optical applications, as shown for the halide-terminated nanoparticles. [ABSTRACT FROM AUTHOR]

Glass transition plays a critical role to determine the dynamic behaviors of amorphous shape memory polymers (SMPs). However, the fundamental relationships between shape memory effect (SME) and dynamic glass transition have not been well understood, even though this topic has been studied for decades. In this study, we apply a mean-square displacement function of Adam-Gibbs (AG) domain size model to explore metastable glass transition between normal glass state and rubbery state of amorphous SMPs, based on both mode-coupling theory and mean-field model. A statistic viscosity equation is formulated to study the dynamic glass transition of metastable AG domains in an amorphous SMP. A dynamically spinodal model is also developed to connect dynamic glass transitions to thermomechanical processes, based on statistic viscosity equation and phase transition model. Furthermore, using the spinodal models, multiple shape memory behaviors have been predicted for amorphous SMPs with dual-, triple- and quadruple-SMEs, resulted from their different routes of themomechanical evolutions. Finally, the proposed models are verified using the experimental data reported in literature. [ABSTRACT FROM AUTHOR]

The crystal phases are essential to the physicochemical properties and functionalities of materials. Copper selenide has emerged as an important and appealing semiconductor, which can exist in a variety of polymorphic phases. However, the richness of polymorphs also makes it a challenge to the direct preparation of copper selenide nanocrystals with tunable phases. Herein, two polymorphs, that is, quasi‐tetragonal Cu2−xSe nanocubes and metastable wurtzite Cu2Se nanodisks, are successfully synthesized by using a single precursor, copper(I) selenocyanate (CuSeCN), as the Cu and Se sources. The key to phase modulation is the optimal choice of the ligand in the synthesis. The as‐prepared nanocrystals possess different morphologies and compositions, giving rise to distinct optical properties and electrical conductivities. Interestingly, the copper selenide nanocrystals can provide a platform for the rational construction of two types of amorphous hollow Au─Cu─Se nanostructures by reaction with Au(I) precursor, in which their final shapes are well kept as that of the original nanocrystal templates. This work provides an easy strategy for the phase‐controlled synthesis of copper selenide nanocrystals and enables the design of new materials for broad applications. [ABSTRACT FROM AUTHOR]

Conventional book casting of Sm2TM17-type alloys (where TM = Co, Fe, Cu, Zr) leads to a coarse, highly segregated microstructure, predominantly due to the slow, variable cooling rate from the mould surface towards the centre of the ingot. These cast alloys require a long homogenisation treatment to remove this segregation and develop a super-saturated, metastable SmTM7-type hexagonal phase. This SmTM7 phase is a vital precursor phase required during magnet production to develop the complex cellular structure responsible for high magnetic properties. In this work, strip casting was employed to facilitate rapid solidification to develop thin flakes (7 phase. This could remove or significantly reduce the need for the energy-intensive homogenisation treatment usually required in conventional magnet manufacture. This paper investigates the effect of wheel speed (and hence cooling rate) on flake thickness, microstructure, and phase balance of the cast alloys. It was shown that for wheel speeds between 1.1 and 3.0 m/s, the microstructure showed large variation; however, in all cases, evidence of the columnar SmTM7 phase was presented. The adhesion between the melt and the wheel was deemed to be critical for the nucleation and subsequent columnar growth of SmTM7 grains, where the wheel speed controlled both the flow of the alloy onto the wheel and the thickness of the resultant flake. It was determined that in order to achieve a homogenous columnar SmTM7 structure, the maximum flake thickness should be limited to 270 μm to avoid the formation of equiaxed Sm2TM17 grains through insufficient cooling.

Recent experimental and theoretical work has demonstrated significant potential to tune the properties of silicon and germanium by adjusting the mesostructure, nanostructure, and/or crystalline structure of these group 14 elements. Despite the promise to achieve enhanced functionality with these already technologically important elements, a significant challenge lies in the identification of effective synthetic approaches that can access metastable silicon and germanium-based extended solids with a particular crystal structure or specific nano/meso-structured features. In this context, the class of intermetallic compounds known as Zintl phases has provided a platform for discovery of novel silicon and germanium-based materials. This review highlights some of the ways in which silicon and germanium-based Zintl phases have been utilized as precursors in innovative approaches to synthesize new crystalline modifications, nanoparticles, nanosheets, and mesostructured and nanoporous extended solids with properties that can be very different from the ground states of the elements.

The limited coercivity (Hc) and metastability of the ferromagnetic τ phase MnAl-C magnet have constrained its magnetic performance and application potential. Bi was doped into the Mn54Al44-xBixC2 alloy system in this study. The doped Bi could effectively stabilize the metastable τ phase and inhibit the non-magnetic Al-rich phase formation. The ferromagnetic τ phase ratio increased dramatically as the doped Bi increase, with a peak Ms of 81 emu/g was achieved for the post-annealed Mn54Al43.6Bi0.4C2 alloy at 19 kOe. High Hc ferromagnetic LTP MnBi phase forms within the Mn54Al44-xBixC2 (x = 0.2, 0.4, 0.6) alloys when it been annealed at 300℃ for 24 h, the samples tripled or even quadrupled in Hc compared with the initial synthesized alloy. The doped Bi dissolved within lattice caused the τ phase thermally stability, structural stability improves substantially; 0.4 Bi doped Mn54Al43.6Bi0.4C2 alloy exhibited a combination of high Ms and Hc even after been ball milled for a long period of 15 and 20 h. The (Ms, Hc) achieved a value of (59.6 emu/g, 3526 Oe) for the 15 h milled sample and (51.5 emu/g, 4546 Oe) for the 20 h milled sample at 19 kOe, respectively; which is desirable for its application as a high-performance rare earth free permanent magnet.

Abstract The crystal phases are essential to the physicochemical properties and functionalities of materials. Copper selenide has emerged as an important and appealing semiconductor, which can exist in a variety of polymorphic phases. However, the richness of polymorphs also makes it a challenge to the direct preparation of copper selenide nanocrystals with tunable phases. Herein, two polymorphs, that is, quasi‐tetragonal Cu2−xSe nanocubes and metastable wurtzite Cu2Se nanodisks, are successfully synthesized by using a single precursor, copper(I) selenocyanate (CuSeCN), as the Cu and Se sources. The key to phase modulation is the optimal choice of the ligand in the synthesis. The as‐prepared nanocrystals possess different morphologies and compositions, giving rise to distinct optical properties and electrical conductivities. Interestingly, the copper selenide nanocrystals can provide a platform for the rational construction of two types of amorphous hollow Au─Cu─Se nanostructures by reaction with Au(I) precursor, in which their final shapes are well kept as that of the original nanocrystal templates. This work provides an easy strategy for the phase‐controlled synthesis of copper selenide nanocrystals and enables the design of new materials for broad applications.

The internal friction among unfluidized particles makes them polymorphic, thus confusing measurements of minimum fluidization velocity (Umf) and segregation index (S). Such a polymorphic characteristic of the packed bed caused the ΔPb–Ug↑ curve measured subsequently to be poorly reproducible. The poor reproducibility of determining Umf from this curve resulted eventually from the ambiguity in the traditional definition of Umf. It did not clearly indicate which of the many states the particles should be initially packed into before measuring the ΔPb–Ug↑ curve. The internal friction caused it difficult to accurately measure S for low gas velocities. The corresponding stable fluidization states could not be obtained through reducing the gas flow slowly from complete fluidization to these velocities. Some particles lost the capability to move before reaching their stable equilibrium positions. Only some steady states which could not represent the given Ug were obtained. Many states of the unfluidized particles were demonstrated to be metastable and belong to the amorphous/glass state. They could not recover/restore themselves after relatively large perturbations. [ABSTRACT FROM AUTHOR]

Block copolymers (BCPs) self-assemble into intricate nanostructures that enhance a multitude of advanced applications in semiconductor processing, membrane science, nanopatterned coatings, nanocomposites, and battery research. Kinetics and thermodynamics of self-assembly are crucial considerations in controlling the nanostructure of BCP thin films. The equilibrium structure is governed by a molecular architecture and the chemistry of its repeat units. An enormous library of materials has been synthesized and they naturally produce a rich equilibrium phase diagram. Non-equilibrium phases could potentially broaden the structural diversity of BCPs and relax the synthetic burden of creating new molecules. Furthermore, the reliance on synthesis could be complicated by the scalability and the materials compatibility. Non-equilibrium phases in BCPs, however, are less explored, likely due to the challenges in stabilizing the metastable structures. Over the past few decades, a variety of processing techniques were introduced that influence the phase transformation of BCPs to achieve a wide range of morphologies. Nonetheless, there is a knowledge gap on how different processive pathways can induce and control the non-equilibrium phases in BCP thin films. In this review, we focus on different solvent-induced and thermally induced processive pathways, and their potential to control the non-equilibrium phases with regards to their unique aspects and advantages. Furthermore, we elucidate the limitations of these pathways and discuss the potential avenues for future investigations. [ABSTRACT FROM AUTHOR]

Thermodynamic properties of homogeneous fluids in the metastable and unstable regions are needed to describe confined fluids, interfaces, nucleating embryos and estimate critical mass flow rates. The most accurate equations of state (EoS) called multiparameter EoS, have a second, non-physical Maxwell loop that renders predictions unreliable in these regions. We elaborate how information from the stable region can be used to reconstruct the metastable and unstable regions. For a simple interaction potential, comparison to results from molecular simulations reveals that isochoric expansion of the pressure from stable states reproduces simulation results in the metastable regions. By constructing a dome that extends above the critical point, we obtain an extrapolated pressure from multiparameter EoS that is free of second Maxwell loops. A reconstructed EoS is developed next, by integrating the extrapolated pressure from a stable state to obtain the Helmholtz energy. The consistency of the reconstructed EoS is gauged by computing phase equilibrium densities, pressures, and enthalpies of evaporation, which are in reasonable agreement with experimental values. Combined with density gradient theory, the reconstructed EoS yields surface tensions of water, carbon dioxide, ammonia, hydrogen and propane that deviate, on average, 4.4%, 1.6%, 6.0%, 0.7% and 5.4% from experimental values respectively. The results reveal a potential to develop more accurate extrapolation protocols, which can be leveraged to obtain prediction of metastable properties, surface properties or used as constraints in fitting multiparameter EoS. [ABSTRACT FROM AUTHOR]

Electrolyte-assisted semiconductors have garnered significant attention as a novel type of semiconductor device due to their unique properties. Notably, the electrolyte-assisted electroluminescent (EEL) device offers several advantages, including a simple structure, low operating voltage, and reduced need for band engineering compared to conventional EL devices. However, achieving practical applications for EEL devices remains challenging due to their inherent issues. In this study, we introduce a yellow-emitting EEL device that utilizes a metastable β-phase Zn 2 SiO 4 :Mn2+ film as the optically functional material. The film is prepared using a cost-effective process, optimizing both the crystallization temperature and the concentration of Mn2+. Additionally, we employ a non-toxic aqueous NaCl as the electrolyte in the device setup. The crystal phase, morphology, optical, and electrical properties, along with reliability, are comprehensively investigated in our study. The results highlight the significance of our proposed work in advancing the development of electrolyte-assisted semiconductors within the realm of silicon photonics. • A yellow electrolyte-assisted electroluminescent (EEL) device is presented using metastable optical material in an electrolyte-silicon semiconductor structure. • The EEL optimum of annealing temperature, dopant, and electro-optical properties are investigated. • The EEL device reliability and post-operation morphology are examined to evaluate the practicality and prospects. [ABSTRACT FROM AUTHOR]

Abstract Establishing covalent heterointerfaces with face-to-face contact is promising for advanced energy storage, while challenge remains on how to inhibit the anisotropic growth of nucleated crystals on the matrix. Herein, face-to-face covalent bridging in-between the 2D-nanosheets/graphene heterostructure is constructed by intentionally prebonding of laser-manufactured amorphous and metastable nanoparticles on graphene, where the amorphous nanoparticles were designed via the competitive oxidation of Sn-O and Sn-S bonds, and metastable feature was employed to facilitate the formation of the C-S-Sn covalent bonding in-between the heterostructure. The face-to-face bridging of ultrathin SnS2 nanosheets on graphene enables the heterostructure huge covalent coupling area and high loading and thus renders unimpeded electron/ion transfer pathways and indestructible electrode structure, and impressive reversible capacity and rate capability for sodium-ion batteries, which rank among the top in records of the SnS2-based anodes. Present work thus provides an alternative of constructing heterostructures with planar interfaces for electrochemical energy storage and even beyond.

Designing a unique metastable interface provides a promising way to achieve high catalytic performance yet remains a great challenge due to the thermodynamics' unstable nature. In this work, we constructed the stabilized metastable interface between metastable ruthenium–nickel alloy and metastable hexagonal–close-packed nickel via a one-step solvothermal method. The optimized nanocatalyst (denoted as hcp RuNi) shows bifunctional performance toward electrochemical hydrogen oxidation and evolution reactions (HOR/HER). Density functional theory calculations reveal that two different reaction sites at the unique interface contribute to the enhanced HER and HOR performances. This work highlights the important role on interface engineering of metastable materials for highly efficient catalysis. [ABSTRACT FROM AUTHOR]

The process related to the formation of a multicomponent amorphous material during the reduction of α-Fe2O3 with the products of thermodestruction of WAS is studied using x-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Because WAS contains sand and clay along with its bio-components, the thermal treatment of WAS is accompanied by the formation of amorphous carbon, SiO2, Al2O3, and multicomponent alloys. At T = 1000 °C, under oxygen-deficient conditions, iron oxide was reduced according to the scheme: α-Fe2O3 → (amorphous phase)main part + (Fe + Fe0.94O)(crystalline)little part. The main product of the Fe2O3 reduction is amorphous iron with a lamellar structure. Newly formed amorphous alloys form interlayers between the iron plates and 3D inclusions. Inclusions of C, SiO2, and Al2O3 agglomerates are observed between the lamellar packs. This macrostructure of the material allows slow cooling of the 3D-samples while preserving the amorphous state of iron.

The quiescent muscle stem cell (QSC) pool is heterogeneous and generally characterized by the presence and levels of intrinsic myogenic transcription factors. Whether extrinsic factors maintain the diversity of states across the QSC pool remains unknown. The muscle fiber is a multinucleated syncytium that serves as a niche to QSCs, raising the possibility that the muscle fiber regulates the diversity of states across the QSC pool. Here, we show that the muscle fiber maintains a continuum of quiescent states, through a gradient of Notch ligand, Dll4, produced by the fiber and captured by QSCs. The abundance of Dll4 captured by the QSC correlates with the protein levels of the stem cell (SC) identity marker, Pax7. Niche-specific loss of Dll4 decreases QSC diversity and shifts the continuum to cell states that are biased toward more proliferative and committed fates. We reveal that fiber-derived Mindbomb1 (Mib1), an E3 ubiquitin ligase activates Dll4 and controls the heterogeneous levels of Dll4. In response to injury, with a Dll4-replenished niche, the normal continuum and diversity of the SC pool is restored, demonstrating bidirectionality within the SC continuum. Our data show that a post-translational mechanism controls heterogeneity of Notch ligands in a multinucleated niche cell to maintain a continuum of metastable states within the SC pool during tissue homeostasis.

The metastable Ni/ZrO 2 catalysts were rationally constructed via reflux treatment and employed for dry reforming of methane. Reflux could suppress the transformation and improve the stability of the metastable ZrO 2 , as well as enrich its pore structure. Meanwhile, acidity-basicity, Zr3+ and oxygen vacancies were also promoted. Additionally, Ni dispersion was remarkably improved with increasing reflux time due to the abundant pores and enhanced metal-support interaction. These results illustrated the evaluation that prolonging reflux time could significantly proliferate the performance of Ni/ZrO 2. Besides, reflux could strengthen the anti-carbon ability but the widened gap between CH 4 dissociation and CO 2 activation would cause more carbon deposition. The catalyst with reflux for 240 h showed the robust stability for 9000 min (CH 4 conversion: 80 %; CO 2 conversion: 88 %) at 750 °C. Furthermore, the mechanisms were discussed to unravel the origin of the accelerated performance by reflux and provide some references for designing efficient Ni-based catalyst. [Display omitted] • Reflux stabilizes the metastable ZrO 2 with abundant pore structure and more acid-base/defect sites. • Reflux enhances metal-support interaction, thereby improving Ni dispersion. • Catalyst after reflux shows higher activity, better stability and stronger anti-carbon ability. • Balancing the rate of CH 4 dissociation and CO 2 activation is crucial for restraining carbon formation. • Reaction mechanisms are discussed to unravel the origin for the performance improvement by reflux. [ABSTRACT FROM AUTHOR]

The study of phase transitions and critical parameters has a history of nearly one century. The interest shown in this field of science has provided an accumulation of knowledge about phase transitions and critical states of matter through significant researches. On the other hand, theoretical and experimental studies still show that the pressure and temperature diagram of the material is not completed. In particular, the absence of plasma in the (p-T) phase diagram, the uncertainty of the pressure-dependent boundary range of the liquid phase and the state of the equilibrium curves are the focus of the studies. In the phase diagram of pure substance (p-T), the representation of only three phases and the boundary curves separating these phases with two basic points limits the phase diagram. However, as long as the plasma, which constitutes 98% of the universe and is accepted as the fourth phase of matter, does not take place in the phase diagram (p-T) and the liquid phase remains uncertain, phase transitions and critical parameters cannot be fully resolved. [ABSTRACT FROM AUTHOR]

Highlights: Face-to-face covalent bridging in-between 2D-nanosheets/graphene heterostructure was constructed by intentionally prebonding of laser-manufactured amorphous and metastable nanoparticles on graphene. The consecutive bonding enables the robust anchoring of ultrathin SnS2 nanosheets on graphene with huge covalent coupling area as well as spontaneous charge transfer in-between the heterostructure. Such laser-manufactured heterostructure is capable of guaranteeing high-flux electron/ion migration and structural integrity upon cycling, thus contributing to the unprecedented Na-storage capability. Establishing covalent heterointerfaces with face-to-face contact is promising for advanced energy storage, while challenge remains on how to inhibit the anisotropic growth of nucleated crystals on the matrix. Herein, face-to-face covalent bridging in-between the 2D-nanosheets/graphene heterostructure is constructed by intentionally prebonding of laser-manufactured amorphous and metastable nanoparticles on graphene, where the amorphous nanoparticles were designed via the competitive oxidation of Sn-O and Sn-S bonds, and metastable feature was employed to facilitate the formation of the C-S-Sn covalent bonding in-between the heterostructure. The face-to-face bridging of ultrathin SnS2 nanosheets on graphene enables the heterostructure huge covalent coupling area and high loading and thus renders unimpeded electron/ion transfer pathways and indestructible electrode structure, and impressive reversible capacity and rate capability for sodium-ion batteries, which rank among the top in records of the SnS2-based anodes. Present work thus provides an alternative of constructing heterostructures with planar interfaces for electrochemical energy storage and even beyond. [ABSTRACT FROM AUTHOR]

Role of surface structure/composition in altering solidification behavior is demonstrated through undercooling of core-shell metal particles. Autonomous surface speciation in the passivating oxide plays a critical role in the relaxation of a molten metal due to divergence in the concentration and composition of oxidizing species across the thickness of the oxide layer. In an unreactive environment, surface speciation is dictated by flux, cohesive energy density, and surface energy minimization. Under oxidizing conditions (e.g., ambient), however, reduction potential, curvature, and surface plasticity dictate the spatial order and concentration(s) across thin passivating oxide layers. It is therefore important to redefine solubility beyond the limitations of Hume-Rothery rules by substituting electronegativity for redox potential and cohesive energy density. Increasing number of components in an alloy does not necessarily lead to increased undercooling, but a maximum is observed around two to three components. These results lead to an empirical observation that ΔG LS (Gibbs' free energy for liquid-solid transition) around the freezing point can be understood from enthalpy and surface tension balance, with the degree of undercooling being a proportionality term for the enthalpic component. This work extends our understanding of classical nucleation theory by illustrating the importance of asymmetry in surface work in phase change, largely due to changes in structure of nanoscale passivating oxides. This phenomena is critical in development of low-temperature solders. [ABSTRACT FROM AUTHOR]

The intergrowth of stable and metastable AgInS2 polymorphs was synthesized using a microwave-assisted synthesis. The samples were synthesized in water and in a deep eutectic solvent (DES) consisting of choline chloride and thiourea. An increase in the metal precursor concentration improved the crystallinity of the synthesized samples and affected the particle size. AgInS2 cannot be synthesized from crystalline binary Ag2S or In2S3 via this route. The solution synthesis reported here results in the intergrowth of the thermodynamically stable polymorph (space group I 4 ¯ 2d, chalcopyrite structure) and the high-temperature polymorph (space group Pna21, wurtzite-like structure) that is metastable at room temperature. A scanning transmission microscopy (STEM) study revealed the intergrowth of tetragonal and orthorhombic polymorphs in a single particle and unambiguously established that the long-thought hexagonal wurtzite polymorph has pseudo-hexagonal symmetry and is best described with the orthorhombic unit cell. The solution-synthesized AgInS2 polymorphs intergrowth has slightly lower bandgap values in the range of 1.73 eV–1.91 eV compared to the previously reported values for tetragonal I 4 ¯ 2d (1.86 eV) and orthorhombic Pna21 (1.98 eV) polymorphs. [ABSTRACT FROM AUTHOR]

Abundant surface structural defects can endow electrocatalysts with extraordinary physical and chemical characteristics. Herein, metastable Pd nanoparticles (NPs) with abundant twin boundaries (TBs) and atomic steps (ASs) anchored on a carbon substrate (TS‐Pd/C) are directly synthesized by a solid‐state thermal shock (TS) strategy. Molecular dynamics simulation indicates that the transient super cooling procedure after the TS synthesis can boost the formation of TBs. Benefitting from the abundant TBs and ASs, these metastable Pd NPs can serve as an advanced electrocatalyst for the ethanol oxidation reaction (EOR) with superior reactivity, stability, and CO tolerance in alkaline solutions, which far exceeds that of commercial Pd/C. The first‐principles calculations suggest that the defect structure dominated by TBs can achieve the spatial separation of the optimal adsorption sites for CO and OH. The CO can concentrate at optimal surface sites to minimize the number of poisoned active sites. The strong adsorption of OH can accelerate the EOR process and jointly promote the improvement of electrocatalytic reactivity. [ABSTRACT FROM AUTHOR]

A lithium-excess cation-disordered rocksalt oxide, Li1.15Nb0.15Mn0.7O2, is synthesized and tested as positive electrode materials for battery applications. Although nanosized Li1.15Nb0.15Mn0.7O2 delivers a large reversible capacity using cationic/anionic redox reaction, the inferior capacity retention hinders its use for practical applications. Such degradation of electrode reversibility, including electrochemical and structural reversibility, is anticipated to originate from the gradual oxygen loss for the electrode materials with anionic redox. Herein, Li3PO4 is integrated into Li1.15Nb0.15Mn0.7O2 by high-energy mechanical milling, and 7 mol% Li3PO4 integrated Li1.15Nb0.15Mn0.7O2, Li1.2P0.06Nb0.13Mn0.61O2, shows much improved cyclability when compared with the sample without Li3PO4. Approximately 80 % of reversible capacity is retained after 100-cycle test at a rate of 200 mA g−1. Moreover, electrode kinetics are significantly improved by Li3PO4 integration, and Li1.2P0.06Nb0.13Mn0.61O2 delivers a discharge capacity of 200 mA h g−1 at a rate of 640 mA g−1. Li1.2P0.06Nb0.13Mn0.61O2 also shows improved thermal stability at elevated temperatures. From these results, the effectiveness of Li3PO4 integration into nanosized disordered rocksalt oxides with anionic redox is discussed, and this finding leads to the development of metastable high-capacity positive electrode materials for advanced Li-ion batteries.

Metallic molybdenum sulfide (1T-MoS2) is considered as the most promising electrocatalyst for the acidic hydrogen evolution reaction (HER). Nevertheless, exploring a facile and effective approach for achieving high-purity 1T-MoS2 is still full of challenges. Herein, we demonstrate a two-dimensional material-assisted confined synthetic strategy, as an available method to construct and stabilize 1T-MoS2. During the hydrothermal process, the interaction between the N source and MoS2 is largely enhanced in a two-dimensional confined reactor, formed by reduced graphene oxides, successfully obtaining a high concentration of 90.1% of 1T-MoS2, named N-MoS2/rGO. The optimal N-MoS2/rGO nanosheets require a low overpotential (130 mV) to reach a current density of 10 mA·cm–2 and a low Tafel slope of 46.5 mV·dec–1. Additionally, they also exhibit high stability for at least 12 h in an acidic electrolyte maintaining 84.2% of the 1T-MoS2 phase. This work opens up an avenue to construct two-dimensional metastable materials for advanced catalysis. [ABSTRACT FROM AUTHOR]

Lithium peroxide is the crucial storage material in lithium-air batteries. Understanding the redox properties of this salt is paramount toward improving the performance of this class of batteries. Lithium peroxide, upon exposure to p-benzoquinone (p-C6H4O2) vapor, develops a deep blue color. This blue powder can be formally described as [Li2O2]0.3 ⋅ [LiO2]0.7 ⋅ {Li[p-C6H4O2]}0.7, though spectroscopic characterization indicates a more nuanced structural speciation. Infrared, Raman, electron paramagnetic resonance, diffuse-reflectance ultraviolet-visible and X-ray absorption spectroscopy reveal that the lithium salt of the benzoquinone radical anion forms on the surface of the lithium peroxide, indicating the occurrence of electron and lithium ion transfer in the solid state. As a result, obligate lithium superoxide is formed and encapsulated in a shell of Li[p-C6H4O2] with a core of Li2O2. Lithium superoxide has been proposed as a critical intermediate in the charge/discharge cycle of Li-air batteries, but has yet to be isolated, owing to instability. The results reported herein provide a snapshot of lithium peroxide/superoxide chemistry in the solid state with redox mediation. [ABSTRACT FROM AUTHOR]

The development of inherently safe energy devices is a key challenge, and aqueous Li-ion batteries draw large attention for this purpose. Due to the narrow electrochemical stable potential window of aqueous electrolytes, the energy density and the selection of negative electrode materials are significantly limited. For achieving durable and high-energy aqueous Li-ion batteries, the development of negative electrode materials exhibiting a large capacity and low potential without triggering decomposition of water is crucial. Herein, a type of a negative electrode material (i.e., LixNb2/7Mo3/7O2) is proposed for high-energy aqueous Li-ion batteries. LixNb2/7Mo3/7O2 delivers a large capacity of ∼170 mA ⋅ h ⋅ g−1 with a low operating potential range of 1.9 to 2.8 versus Li/Li+ in 21 m lithium bis(trifluoromethanesulfonyl)amide (LiTFSA) aqueous electrolyte. A full cell consisting of Li1.05Mn1.95O4/Li9/7Nb2/7Mo3/7O2 presents high energy density of 107 W ⋅ h ⋅ kg−1 as the maximum value in 21 m LiTFSA aqueous electrolyte, and 73% in capacity retention is achieved after 2,000 cycles. Furthermore, hard X-ray photoelectron spectroscopy study reveals that a protective surface layer is formed at the surface of the negative electrode, by which the high-energy and durable aqueous batteries are realized with LixNb2/7Mo3/7O2. This work combines a high capacity with a safe negative electrode material through delivering the Mo-based oxide with unique nanosized and metastable characters. [ABSTRACT FROM AUTHOR]

Robust anchoring of high‐capacity nanocrystals (NCs) on porous conductive substrates is of paramount importance but it is challenging for highly efficient energy storage to prevent the weak interfacial interactions, inevitable aggregation, and sluggish charge transfer, due to the technical hurdles of constructing heterostructures with firm electron/ion bridging. Herein, a facile and high‐efficiency liquid‐phase laser manufacturing strategy to guarantee the covalent bonding of ultrafine NCs on conductive substrates by predesigning metastable supranano (<10 nm) particles is proposed. The manufacturing of supranano SnO2 (≈3.4 nm) is demonstrated to tightly anchor on mesoporous walls of graphene with high loading (≈81.3%) and homogenous dispersion. Such a optimized heterostructure with unimpeded electron/ion transfer delivers extraordinary long‐term cycling stability (1132 mAh g–1 at 1.0 A g–1 after 1250 cycles) and impressive rate capability (275 mAh g–1 at 30.0 A g–1) as the anode for Li‐storage, which are some of the highest values among the reported SnO2‐based anodes. The study provides an important avenue for addressing the interfacial bridging in‐between heterostructures via creating active metastable supranano particles for intriguing electrochemical applications or even beyond, based on laser‐matter interactions. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the effect of niobium on the microstructure and mechanical properties of Ti-Mo-Nb alloys, which include Ti-11.1Mo-10.8Nb (TMN1), Ti-10.2Mo-19.5Nb (TMN2), and Ti-9.2Mo-26.7Nb (TMN3) alloys designed using the cluster-plus-glue-atom model. The molybdenum equivalence, average electron concentration ratio, and d-electron method approaches were used to predict the stability of the β phase. Microstructural analysis was performed using x-ray diffraction, optical microscopy, and electron backscatter diffraction, while the microhardness tests, tensile tests, and bend tests were also conducted. The microstructure of the TMN alloys comprised primarily the β phase and secondary martensitic α″ and athermal ωath phases. Their elastic moduli of the TMN alloys were far greater than those of the common orthopedic implant materials. The alloys showed superior tensile strengths, bend strengths, and microhardness due to the solid solution effect of both Mo and Nb and the precipitation hardening of the ωath. Brittle fracture resulting from the existence of the ωath phase in the alloys was also observed. The designed metastable TMN alloys designed using a synergic combination of the approaches of the cluster-plus-glue-atom model and the β-phase predicting tools can be promising candidates for orthopedic applications. [ABSTRACT FROM AUTHOR]

We developed a series of Co-rich CoxCr25(FeNi)75−x (x = 35, 45, 55, 65) high entropy alloys with improved strength and/or ductility, derived from lowering the stacking fault energy (SFE) and reducing the fcc phase stability of the equiatomic CoCrFeNi alloy. Thermodynamics and ab initio calculations demonstrated that increasing Co while decreasing Fe and Ni concentrations lower the SFE and reduce the fcc phase stability. The Co35Cr25Fe20Ni20 and Co45Cr25Fe15Ni15 alloys with single fcc phase, exhibit superior tensile properties, contributing to the twinning and fcc → hcp martensitic transformation. The present study offers a guideline for designing high-performance high entropy alloys.