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In multicomponent lattice problems, for example, in alloys and at crystalline surfaces and interfaces, atomic arrangements exhibit spatial correlations that dictate the kinetic and thermodynamic phase behavior. These correlations emerge from interparticle interactions and are frequently reported in terms of the short-range order (SRO) parameter. Expressed usually in terms of pair distributions and other cluster probabilities, the SRO parameter gives the likelihood of finding atoms/molecules of a particular type in the vicinity of other atoms. This study focuses on fundamental constraints involving the SRO parameters that are imposed by the underlying lattice topology. Using a data-driven approach, we uncover the interrelationships between different SRO parameters (e.g., pairs, triplets, and quadruplets) on a lattice. The main finding is that while some SRO parameters are independent, the remaining are collinear, i.e., the latter are dictated by the independent ones through linear relationships. A kinetic and thermodynamic modeling framework based on these constraints is introduced. [ABSTRACT FROM AUTHOR]

Phonon diffraction and interference patterns are observed at the atomic scale, using molecular dynamics simulations in systems containing crystalline silicon and nanometric obstacles, such as voids or amorphous inclusions. The diffraction patterns due to these nano-architectured systems of the same scale as the phonon wavelengths are similar to the ones predicted by the simple Fresnel–Kirchhoff integral. The few differences between the two approaches are attributed to the nature of the interface and the anisotropy of crystalline silicon. Based on the wave description of phonons, these findings can provide insights into the interaction of phonons with nano-objects and can have applications in smart thermal energy management. [ABSTRACT FROM AUTHOR]

Amorphous titanium dioxide (a-TiO2) is widely used as a coating material in applications such as electrochemistry and self-cleaning surfaces where its interface with water has a central role. However, little is known about the structures of the a-TiO2 surface and aqueous interface, particularly at the microscopic level. In this work, we construct a model of the a-TiO2 surface via a cut-melt-and-quench procedure based on molecular dynamics simulations with deep neural network potentials (DPs) trained on density functional theory data. After interfacing the a-TiO2 surface with water, we investigate the structure and dynamics of the resulting system using a combination of DP-based molecular dynamics (DPMD) and ab initio molecular dynamics (AIMD) simulations. Both AIMD and DPMD simulations reveal that the distribution of water on the a-TiO2 surface lacks distinct layers normally found at the aqueous interface of crystalline TiO2, leading to an ∼10 times faster diffusion of water at the interface. Bridging hydroxyls (Ti2–ObH) resulting from water dissociation decay several times more slowly than terminal hydroxyls (Ti–OwH) due to fast Ti–OwH2 → Ti–OwH proton exchange events. These results provide a basis for a detailed understanding of the properties of a-TiO2 in electrochemical environments. Moreover, the procedure of generating the a-TiO2-interface employed here is generally applicable to studying the aqueous interfaces of amorphous metal oxides. [ABSTRACT FROM AUTHOR]

• A highly crystalline BiOBr (c-BiOBr) is synthesized by a two-step process. • A high crystallinity of c-BiOBr enhances the interaction of pollutant and [Bi 2 O 2 ]2+. • The adsorbed pollutant on c-BiOBr plays a role of molecular modification. • The molecular modification effect facilitates the direct pollutant oxidation. • The active electron transfer from pollutant promotes the generation of more O 2 •–. The adsorption of pollutants can not only promote the direct surface reaction, but also modify the catalyst itself to improve its photoelectric characteristics, which is rarely studied for water treatment with inorganic photocatalyst. A highly crystalline BiOBr (c-BiOBr) was synthesized by a two-step preparation process. Owing to the calcination, the highly crystalline enhanced the interface interaction between pollutant and c-BiOBr. The complex of organic pollutant and [Bi 2 O 2 ]2+ could promote the active electron transfer from the adsorbed pollutant to c-BiOBr for the direct pollutant degradation by holes (h+). Moreover, the pollutant adsorption actually modified c-BiOBr and promoted more unpaired electrons, which would coupling with the photoexcitation to promote generate more O 2 •–. The molecular modification effect derived from pollutant adsorption significantly improved the removal of pollutants. This work strongly deepens the understanding of the molecular modification effect from the pollutant adsorption and develops a novel and efficient approach for water treatment. [ABSTRACT FROM AUTHOR]

The exceptionally low reflectance of black silicon (Si) across a broad wavelength range makes it an intriguing surface texture for solar cell applications. Si heterojunction (SHJ) solar cells fabricated on black Si formed by dry reactive ion etching using inductive coupled plasma on n-type Si are explored. The study is focused on the properties of the a-Si:H/ crystalline silicon interface, being a key issue for the photovoltaic performance of SHJ. Deep-level transient spectroscopy detected no radiation defect in Si after the etching. The surface of black Si was passivated with an intrinsic a-Si:H layer, followed by the deposition of p-type and n-type a-Si:H on the front and back sides, respectively. The SHJ solar cell photovoltaic performance based on black Si is strongly influenced by defect density at the a-Si:H/Si interface. Admittance spectroscopy and effective charge carrier lifetime measurements demonstrate that interface defect density decreases with the increase of (i) a-Si:H thickness. The value of 0.75 ms effective charge carrier lifetime was reached for single (i) a-Si:H layer passivation and 0.25 ms when (p)a-Si:H was deposited over the intrinsic a-Si:H layer. The measured open circuit voltage values for the SHJ solar cells increase with the (i) a-Si:H layer thickness reaching 658 mV. However, the fill factor decreases with increasing (i) a-Si:H layer thickness, limiting the efficiency at the maximum value below 14% due to the thickness uniformity of the a-Si:H layer. The development of conformal growth of a-Si:H is a key issue for further improvement of black Si heterojunction solar cell photovoltaic performance. [ABSTRACT FROM AUTHOR]

Room‐temperature sodium‐sulfur (RT Na−S) batteries, noted for their low material costs and high energy density, are emerging as a promising alternative to lithium‐ion batteries (LIBs) in various applications including power grids and standalone renewable energy systems. These batteries are commonly assembled with glass fiber membranes, which face significant challenges like the dissolution of polysulfides, sluggish sulfur conversion kinetics, and the growth of Na dendrites. Here, we develop an amorphous two‐dimensional (2D) iron tin oxide (A‐FeSnOx) nanosheet with hierarchical vacancies, including abundant oxygen vacancies (Ovs) and nano‐sized perforations, that can be assembled into a multifunctional layer overlaying commercial separators for RT Na−S batteries. The Ovs offer strong adsorption and abundant catalytic sites for polysulfides, while the defect concentration is finely tuned to elucidate the polysulfides conversion mechanisms. The nano‐sized perforations aid in regulating Na ions transport, resulting in uniform Na deposition. Moreover, the strategic addition of trace amounts of Ti3C2 (MXene) forms an amorphous/crystalline (A/C) interface that significantly improves the mechanical properties of the separator and suppresses dendrite growth. As a result, the task‐specific layer achieves ultra‐light (~0.1 mg cm−2), ultra‐thin (~200 nm), and ultra‐robust (modulus=4.9 GPa) characteristics. Consequently, the RT Na−S battery maintained a high capacity of 610.3 mAh g−1 and an average Coulombic efficiency of 99.9 % after 400 cycles at 0.5 C. [ABSTRACT FROM AUTHOR]

CoMnOx catalysts were prepared using a microwave (MW)/ultrasonic (US)-assisted method. Amorphous/crystalline regions in CoMnOx (MW = 250 W US = 300 W) increased the oxygen vacancy content and CoMnOx exhibited excellent activity for methane oxidation (T90 = 330 °C). A new approach is provided here to improve the activity of transition metal catalysts. [ABSTRACT FROM AUTHOR]

Compared to Ir, Ru‐based catalysts often exhibited higher activity but suffered significant and rapid activity loss during the challenging oxygen evolution reaction (OER) in a corrosive acidic environment. Herein, we developed a hybrid MnRuOx catalyst in which the RuO2 microcrystalline regions serve as a supporting framework, and the amorphous MnRuOx phase fills the microcrystalline interstices. In particular, the MnRuOx‐300 catalyst from an annealing temperature of 300 °C contains an optimal amorphous/crystalline heterostructure, providing substantial defects and active sites, facilitating efficient adsorption and conversion of OH−. In addition, the heterostructure leads to a relative increase of the d‐band center close to the Fermin level, thus accelerating electron transfer with reduced charge transfer resistance at the active interface between crystalline and amorphous phases during the OER. The catalyst was further thoroughly evaluated under various operating conditions and demonstrated exceptional activity and stability for the OER, representing a promising solution to replace Ir in water electrolyzers. [ABSTRACT FROM AUTHOR]

Heterostructures comprising NiCoP and NiCo 2 S 4 (referred to as NCP/NCS) were created by incorporating P and S elements into NiCo 2 O 4 (NCO) micro-nanospheres through phosphorization and hydrothermal sulfurization processes. Selective construction of heterogeneous structures can balance the advantages and disadvantages of each single component and is desirable in HER applications. In alkaline media, the resulting product NCP/NCS had an overpotential of 195 mV at a current density of 10 mA cm−2, which is 337 mV higher than that of the original NCO and significantly better than the products of pure phosphide (NCP) and sulfide (NCS). Its Tafel slope was about 83 mV dec−1 and the HER performance did not decay significantly over 48 h. On the other hand, the formation of heterogeneous interfaces improves the intrinsic catalytic activity of the materials. Density functional theory (DFT) simulations show that the hydrogen adsorption capacity at the heterogeneous interface is optimized due to charge enrichment, which in turn enhances the intrinsic activity. • Micro-nanospheres heterostructures was prepared via gas-liquid diffusion method. • Morphology characterization displays the obvious interface and crystalline surface. • The heterostructures delivers a low overpotential than that of single component. • Density functional theory reveals the heterogeneous interface enhance hydrogen adsorption. [ABSTRACT FROM AUTHOR]

The efficiency of an organic solar cell is highly dependent on the complex, interpenetrating morphology, and molecular order within the composite phases of the bulk heterojunction (BHJ) blend. Both these microstructural aspects are strongly influenced by the processing conditions and chemical design of donor/acceptor materials. To establish improved structure‐function relationships, it is vital to visualize the local microstructural order to provide specific local information about donor/acceptor interfaces and crystalline texture in BHJ blend films. The visualization of nanocrystallites, however, is difficult due to the complex semi‐crystalline structure with few characterization techniques capable of visualizing the molecular ordering of soft materials at the nanoscale. Here, it is demonstrated how cryo‐electron microscopy can be utilized to visualize local nanoscale order. This method is used to understand the distribution/orientation of crystallites in a BHJ blend. Long‐range (>300 nm) texturing of IEICO‐4F crystallites oriented in an edge‐on fashion is observed, which has not previously been observed for spin‐coated materials. This approach provides a wealth of quantitative information about the texture and size of nanocrystallites, which can be utilized to understand charge generation and transport in organic film. This study guides tailoring the material design and processing conditions for high‐performance organic optoelectronic devices. [ABSTRACT FROM AUTHOR]

Amorphous/crystalline high-entropy-alloy (HEA) composites show great promise as structural materials due to their exceptional mechanical properties. However, there is still a lack of understanding of the dynamic nanoindentation response of HEA composites at the atomic scale. Here, the mechanical behavior of amorphous/crystalline HEA composites under nanoindentation is investigated through a large-scale molecular dynamics simulation and a dislocation-based strength model, in terms of the indentation force, microstructural evolution, stress distribution, shear strain distribution, and surface topography. The results show that the uneven distribution of elements within the crystal leads to a strong heterogeneity of the surface tension during elastic deformation. The severe mismatch of the amorphous/crystalline interface combined with the rapid accumulation of elastic deformation energy causes a significant number of dislocation-based plastic deformation behaviors. The presence of surrounding dislocations inhibits the free slip of dislocations below the indenter, while the amorphous layer prevents the movement or disappearance of dislocations towards the substrate. A thin amorphous layer leads to great indentation force, and causes inconsistent stacking and movement patterns of surface atoms, resulting in local bulges and depressions at the macroscopic level. The increasing thickness of the amorphous layer hinders the extension of shear bands towards the lower part of the substrate. These findings shed light on the mechanical properties of amorphous/crystalline HEA composites and offer insights for the design of high-performance materials. [ABSTRACT FROM AUTHOR]

A novel strategy is proposed in this work to accelerate proton-coupled electron transfer via phase-engineered amorphous/crystalline interface for advancing overall water splitting. [Display omitted] • Co/Co 2 C crystals have been assembled on amorphous N, S co-doped porous carbon through hydrothermal and calcination process. • The stable biphase structure and amorphous/crystalline interface enhances the conductivity and intrinsic activity. • The adsorption ability of water molecules and intermediates is improved significantly. • This work has pioneered the crystalline/amorphous phase in electrocatalysts and provided new insights into phase engineering. Traditional phase engineering enhances conductivity or activity by fully converting electrocatalytic materials into either a crystalline or an amorphous state, but this approach often faces limitations. Thus, a practical solution entails balancing the dynamic attributes of both phases to maximize an electrocatalyst's functionality is urgently needed. Herein, in this work, Co/Co 2 C crystals have been assembled on the amorphous N, S co-doped porous carbon (NSPC) through hydrothermal and calcination processes. The stable biphase structure and amorphous/crystalline (A/C) interface enhance conductivity and intrinsic activity. Moreover, the adsorption ability of water molecules and intermediates is improved significantly attributed to the rich oxygen-containing groups, unsaturated bonds, and defect sites of NSPC, which accelerates proton-coupled electron transfer (PCET) and overall water splitting. Consequently, A/C-Co/Co 2 C/NSPC (Co/Co 2 C/NSPC with amorphous/crystalline interface) exhibits outstanding behavior for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), requiring the overpotential of 240.0 mV and 70.0 mV to achieve 10 mA cm−2. Moreover, an electrolyzer assembled by A/C-Co/Co 2 C/NSPC-3 (anode) and A/C-Co/Co 2 C/NSPC-2 (cathode) demonstrates a low drive voltage of 1.54 V during overall water splitting process. Overall, this work has pioneered the coexistence of crystalline/amorphous phases in electrocatalysts and provided new insights into phase engineering. [ABSTRACT FROM AUTHOR]

This study introduces the development of a novel bio-nano composite via the dispersion of cellulose nanofibers (CNF) in epoxy. The surface of cellulose nanofibers was functionalized using a two-step chemical treatment to enhance dispersion. The interfacial characteristics of CNF were improved using alcohol/acetone treatments. The modified CNF (M-CNF) demonstrated enhanced compatibility and improved dispersion in the epoxy matrix as evidenced by scanning electron microscopy. Based on the analysis of X-ray diffraction patterns, M-CNF did not disturb the crystalline phases at the interface. The results of mechanical testing showed that M-CNF worked as a reinforcing agent in the bio-nano composite. The flexural modulus increased from 1.4 to 3.7 GPa when M-CNF was introduced. A similar trend was observed for tensile strength and impact resistance. The optimum performance characteristics were observed at M-CNF of 0.6%. At higher dosages, some agglomeration was observed, which weakened the interfacial properties. This study promotes sustainability and resource conservation while offering CNF as a sustainable reinforcing agent to develop bio-nano composites. [ABSTRACT FROM AUTHOR]

The degradation of microplastics in relation to marine pollution has been receiving increasing attention. Because the spherulites that comprise microplastics have a highly ordered lamellar structure, their decomposition is thought to involve a lamellar structure collapse process. However, even in the simplest case of an order–disorder transition between lamellae and melt upon heating, the microscopic details of the transition have yet to be elucidated. In particular, it is unclear whether nucleation occurs at defects in the crystalline portion or at the interface between the crystalline and amorphous portions. To observe the transition in molecular simulations, an approach that distinguishes between the crystalline and amorphous structures that make up the lamella is needed. Local order parameters (LOPs) are an attempt to define the degree of order on a particle-by-particle basis and have demonstrated the ability to precisely render complex order structure transitions during phase transitions. In this study, 274 LOPs were considered to classify the crystalline and amorphous structures of polymers. Supervised machine learning was used to automatically and systematically search for the parameters. The identified optimal LOP does not require macroscopic information such as the overall orientation direction of the lamella layers but can precisely distinguish the crystalline and amorphous portions of the lamella layers using only a small amount of neighboring particle information. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction reaction (CO2RR) provides a promising way for producing value‐added fuels and chemicals via renewable electricity. However, the dynamic reconstruction of electrocatalysts of atomic active sites hinders in‐depth understanding of catalytic mechanism and further industrial application, especially under ampere‐level current density conditions. In this work, electro‐induced crystallization is reported over an amorphous Indium hydroxide gel (In gel) catalyst, which generates active sites for efficient and selective CO2RR. Molecular dynamic calculation reveals the crystallization process can maintain amorphous In‐OH species on the surface while generating crystallized metallic In under electroreduction condition; structural characterizations prove that the derived partially crystallized In gel is stable consisting of amorphous/crystalline interface, even biased at a high polarization potential of −4 V versus reversible hydrogen electrode. The resultant partially crystalized In gel exhibits a highly selective CO2RR performance toward formate under an ampere‐level current density up to 1200 mA cm−2 simultaneously with 91.89% Faradaic efficiency, which can motivate a high formate generation rate of 20.55 mmol h−1 cm−2. The operando Raman spectroscopic and density functional theoretic results demonstrate the optimized adsorption of *HCOO intermediate for the enhanced formate activity and selectivity over the partially crystallized In gel. [ABSTRACT FROM AUTHOR]

Nickel-rich LiNixCoyMn1−x−yO2 cathode materials have been studied to increase the energy density of lithium-ion batteries due to their high capacity and low cost. However, the complex side reaction in the electrode/electrolyte interphase and cracks inside the secondary particles would decrease the stability of crystalline structure and interface, which further affects the cycling life. Here, a thermodynamically stabilized interface was constructed on the surface of single crystalline nickel-rich cathode material via an acid solution treatment. Structural characterization results confirm the enhanced structural reversibility during electrochemical cycling. Electrochemical data suggests accelerated kinetics for lithium ion diffusion process after treatment. Consequently, modified nickel-rich material delivers significantly enhanced capacity from 131.0 mAh/g for pristine material to 266.2 mAh/g at 0.1 C rate and improved cycling stability. These results suggest it is a moderate method for optimizing the available capacity of high-Ni cathode materials. [ABSTRACT FROM AUTHOR]

Although XLPE cables are widely used in power transmission and distribution systems, their insulating properties are susceptible to degradation due to thermal aging. In order to clarify the influence law of the thermal aging process on the structural and dielectric properties of XLPE cables, this paper investigates the thermal aging characteristics of XLPE cables by using polarization and depolarization current measurement. Results show that when the XLPE cable is aged at 140 °C, the crystallinity of the insulation layer appears to increase and then decrease. With the increase in aging time, micron-sized microvoids appear on the surface of the XLPE. At the same time, the DC conductivity and 0.1 Hz dielectric loss factor of the insulating layer increase with the aging time. The average DC conductivity increased from 2.26 × 10−16 S/m for new cables to 4.47 × 10−16 S/m after aging for 432 h, while the dielectric loss increased from 0.11% to 0.42%. The polarization characteristics of thermal-aged cables were further analyzed using the extended Debye model. Results indicate that the time constant of the third branch of the model increased significantly with increasing aging time. A correspondence between this parameter and the thermal aging time of the cable was established. Thermal aging can damage the crystalline structure of XLPE, so that the number of interfaces between the crystalline and amorphous regions of the material increases, resulting in structural damages and a decline in the dielectric properties of the cable insulation. [ABSTRACT FROM AUTHOR]

We report different growth modes and corresponding magnetic properties of thin EuSe films grown by molecular beam epitaxy on BaF2, Pb1−xEuxSe, GaAs, and Bi2Se3 substrates. We show that EuSe grows predominantly in the (001) orientation on GaAs(111) and Bi2Se3, but along the (111) crystallographic direction on BaF2 (111) and Pb1−xEuxSe (111). High resolution transmission electron microscopy measurements reveal a sharp and highly crystalline interface for both (001) and (111) EuSe films. In agreement with previous studies, ordered magnetic phases include antiferromagnetic, ferrimagnetic, and ferromagnetic phases. In contrast to previous studies, we found a strong hysteresis of the antiferromagnetic–ferrimagnetic transition. The ability to grow epitaxial films of EuSe on Bi2Se3 and of Bi2Se3 on EuSe enables further investigation of interfacial exchange interactions between various phases of an insulating metamagnetic material and a topological insulator. [ABSTRACT FROM AUTHOR]

The interfacial stiffness for nematic–smectic B (nm–smB) interface in a liquid crystalline (LC) material is calculated using Capillary Wave Theory (CWT) and molecular dynamics simulations. The Gay–Berne (GB) pair potential with parameters κ, κ′, μ, and ν equal to 3, 5, 2, and 1 is used to model the LC material. Using a smart three-step recipe, we have obtained an nm–smB phase coexistence in our simulations where the nm and smB directors are nearly parallel to each other and perpendicular to the interface normal. The density profiles are used to compute the nm–smB coexisting density range, the interfacial width, and its position. The smectic phase is differentiated from the nematic phase by using the local bond order parameter (q6q6), which has helped us to demonstrate that the interface is indeed rough. Finally, the interfacial stiffness of the nm–smB interface is computed by following the CWT analysis and is found to be γ ̃ n m − s m B = 0.398 61 k B T / σ e e 2 = 0.044 29 / σ s s 2 , where σee and σss are the length and diameter of the GB LC particles. [ABSTRACT FROM AUTHOR]

A major challenge with water splitting technology is to develop highly active and stable electrocatalysts for the oxygen evolution reaction (OER). IrO2 – based electrocatalysts are one of the most active electrocatalysts for proton exchange membrane (PEM) electrolysers, due to their excellent activity for the OER in acidic conditions. However, IrO2 often suffers from dissolution during electrolysis due to phase transitions into more soluble forms. Herein, a range of electrodeposited IrO2 films annealed to different temperatures of up to 500°C are prepared to understand the influence that crystalline/amorphous interfaces have on performance during accelerated degradation tests in concentrated acidic solutions. This study showed that an IrO2 film annealed at 300 °C exhibited the highest catalytic activity with a low overpotential of 150 mV at 10 mA cm−2, the smallest Tafel slope of 51 mV dec−1, with a less progressive decay in activity over a period of 8 h of accelerated degradation testing. This contrasts with both fully amorphous or more crystalline IrO2 films that decayed much more rapidly within 1 h of testing indicating the role that amorphous/crystalline regions have on OER performance. [ABSTRACT FROM AUTHOR]

Interface engineering shows distinct advantages in the electrocatalytic hydrogen evolution reaction (HER) due to the unique structures that can be realized. The interfaces formed by amorphous materials often exhibit special properties that are beneficial for the HER. Herein, an amorphous/crystalline Rh(OH)3/CoP heterostructure is constructed, which exhibits outstanding HER performance in the all‐pH range. It only needs the overpotentials of 13, 12, and 25 mV to drive a current density of 10 mA cm−2 in alkaline, acidic, and neutral media, respectively, which ranks as one of the best HER electrocatalysts reported recently. The outstanding HER activities in the all‐pH range are attributed to the unique amorphous/crystalline heterostructure of Rh(OH)3/CoP, which possesses special hydrophilic/aerophobic features thataccelerate mass transfer, and provide abundant exposed active sites and appropriate defects. Importantly, the performance attenuation mechanism of the catalyst is also revealed, i.e., the formation of Rh aggregations leads to poor contact and efficacy loss of the amorphous/crystalline interface for HER. In short, this work provides a new idea for using amorphous/crystalline heterostructure to design electrocatalysts, not only for the HER, but also for the oxygen reduction and oxygen evolution reactions. [ABSTRACT FROM AUTHOR]

The technological advances in wearable electronics and military stealth have spawned extensive research into electromagnetic wave absorbents. Despite the rapid progress in the geometrical modulation of magnetic absorbents, the engineering strategy of microwave-responsive magnetic domains is underdeveloped and the response dynamics remain unclear. Herein, a surface finite-sized atom reconstruction procedure is proposed to accurately modulate the local magnetic topological domains, dramatically enhancing the magnetic loss capacity. Due to the selectivity of atom reconstruction, vortex and stripe domains are controllably hybridized around the porous surface to broaden the interactive domain region, significantly intensifying energy absorption of the microwave field. Meanwhile, the amorphous/crystalline interfaces around atom reconstruction regions can induce interfacial polarization, enabling the optimization of dielectric loss capacity. Therefore, a satisfactory magnetic-dielectric synergy is realized to demonstrate the strong absorption intensity of-31.2 dB and the broad absorption bandwidth of 5.9 GHz. Furthermore, the surface-based magnetic domain transformation and microwave energy attenuation mechanisms are thoroughly revealed to break the black box of structure-function through electron holography and micromagnetic simulation. These achievements demonstrate a promising solution to improve high-frequency magnetic properties and provide a feasible route to interpret the structure-relevant magnetic loss capacity. [ABSTRACT FROM AUTHOR]

Conducting oxide interfaces have attracted considerable attention, motivated by both fundamental science and potential for oxide electronic devices. An important gap for maturing such device technology is scalability and routes to control the electronic properties, which can narrow the device engineering space. Here, we demonstrate and explain the mechanisms of highly tunable conductive oxide interfaces. We synthesized amorphous--crystalline Al2O3/SrTiO3 interfaces using the scalable and industry-compatible atomic layer deposition (ALD) technique. An NH3 plasma pretreatment is employed in the ALD chamber, and its duration is used as a tuning parameter for the electrical properties, where a span of three orders of magnitude in the sheet resistance is observed at room temperature. For the most conductive sample, our results are comparable to the highest carrier density values reported for all-crystalline oxide interfaces prepared with state-of-the-art epitaxial growth techniques, such as pulsed laser deposition. We pinpoint the origin of conductivity to oxygen vacancies caused by the SrTiO3 reduction by the NH3 plasma pretreatment. These results present a simple, scalable, and industry-compatible route for realizing conductive oxide interfaces, with a broad parameter space, offering a versatile and flexible toolkit for oxide device engineering. [ABSTRACT FROM AUTHOR]

Nanofibrillated cellulose (NFC) consists of ultrafine cellulose structures in which the fibrils can have widths in the range from about 5 to 100 nm. NFC has been studied and developed in the paper industry, using bleached pulp from wood as the raw material. One of the issues in the application of NFC is their heat resistance to thermal degradation. The production process of NFC results in a decrease in their pyrolysis temperature during the nanofibrillation of bleached pulp; however, the details behind the reason and mechanisms are still unclear. In this study, NFC was prepared from bleached hardwood and softwood pulp by mechanical nanofibrillation using a grinder, and the pyrolysis behavior was investigated. For both bleached pulps, a decrease in the pyrolysis temperature was observed after nanofibrillation. The results suggest that the decrease in the pyrolysis temperature from nanofibrillation is not due to damage of the crystalline cellulose by nano fibrillation, but the damage of the hemicellulose components in the surface of the cellulose microfibrils or the interface between the crystalline cellulose and hemicellulose. If the hemicellulose on the surface of crystalline cellulose could be removed from the NFC, then the decrease in the pyrolysis temperature could be suppressed. [ABSTRACT FROM AUTHOR]

The influence of uniaxial elastic strain of the Ni lattice on the intensity of mutual diffusion at a solid–liquid contact of Ni and Al has been studied by the molecular dynamics method. In all the cases under consideration, the intensity of diffusion has been found to increase and decrease upon extension and compression, respectively, which is related to a corresponding change in the free volume affecting to a great extent the diffusion mobility of atoms. It has been established that the intensity of mutual diffusion in the case of the (111) interface orientation relative to the Ni lattice is higher in comparison with the (001) orientation. This difference is explained by the different energies of Ni atoms in the aluminum phase and incorporated in the interface of crystalline nickel for both cases. [ABSTRACT FROM AUTHOR]

We investigate the magneto-optical (MO) polar Kerr enhancement of Fabry–Pérot cavities with perpendicular magnetic anisotropy for chemical and biological sensing applications. The MO cavities consist of stacked films with a half-mirrored surface layer, a dielectric interference layer, a total-reflection mirror, and a magnetic metal layer. Co80Pt20 and Al-doped ZnO (AZO) thin films were utilized as the magnetic and interference layers, respectively. The cavities produce two types of MO enhancement depending on the thickness of the magnetic layer. The sample with a thick magnetic layer as a total-reflection mirror generates a single peak in the polar Kerr spectrum. Contrarily, inserting a several-nanometer-thick CoPt layer into the AZO layer produces a resonant-type spectrum. Although both samples generate large MO enhancement factors (>50), the magnetic properties significantly differ. The AZO/CoPt/AZO interference layer controls the crystalline and interface conditions and produces a square-shaped out-of-plane hysteresis loop with a large Kerr rotation angle. Moreover, the use of an ultrathin CoPt film significantly reduces the saturation magnetization field. Thus, Fabry–Pérot cavities with a CoPt/AZO interference layer may serve as high-sensitivity, low-energy-consumption sensor elements. [ABSTRACT FROM AUTHOR]

We calculate the degree to which the final structure of the local groundstate in a liquid is a function of the strength of a perturbing potential applied during energy minimization. This structural susceptibility is shown to correlate well with the observed tendency of the liquid adjacent to a crystal interface to exhibit a crystalline groundstate, a feature that has been strongly linked to the observation of ultra-fast crystal growth in pure metals and ionic melts. It is shown that the structural susceptibility increases dramatically as the interaction potential between atoms is softened. [ABSTRACT FROM AUTHOR]

Spherulite-related space–charge electret properties of polypropylene (PP) have been widely discussed in the past decades. In the present paper, a less-common crystalline structure in PP—transcrystalline PP—is studied regarding its electret behavior in comparison with the typical spherulitic morphology. Polarized light microscopy and differential scanning calorimetry were employed to characterize the crystallite types and crystallinities of transcrystalline and spherulitic PP. Their electret functionality is investigated by means of thermally stimulated discharge experiments, where the cross-over phenomenon is observed on transcrystalline PP films, whereas surface-potential saturation and undercharging on the surface occur on the spherulitic samples. Besides, an asymmetrical behavior of positive and negative surface-charge stabilities is found on PP with spherulites, the negatively charged spherulitic surfaces show a better charge stability. It is shown that PP electrets are very sensitive to changes in the microscopic crystalline structures and their interfaces as well as in the molecular conformations controlled through adjustments of the respective processing steps. In addition, surface and bulk nanocomposites of PP or low-density polyethylene with inorganic particles are included in the comparison. In view of recent developments in the areas of PP-based electret-fiber filters and cellular-foam ferroelectrets, the observed changes in the charge-storage properties may have particular relevance, as the required film, fiber, or foam processing might significantly modify crystalline morphologies and nano-scale interfaces in PP electrets. Limitations in the charge-storage capabilities of interface structures may also be of interest in the context of high-voltage electrical-insulation materials where reduced space–charge accumulation and slightly increased charge transport can be advantageous. [ABSTRACT FROM AUTHOR]

Crystallization processes of amorphous germanium–tin (GeSn) under low-energy electron-beam irradiation were examined using transmission electron microscopy (TEM). Freestanding amorphous GeSn thin films were irradiated with a 100 keV electron beam at room temperature. The amorphous GeSn was athermally crystallized by electron-beam irradiation, when the electron flux exceeded the critical value. Heterogeneous structures consisting of nano- and micro-crystallites were formed after crystallization of amorphous GeSn with ∼24 at. % Sn in the as-sputtered amorphous state. In situ TEM observations of structural changes under electron-beam irradiation revealed that random nucleation and growth of nanocrystallites occur at the early stage of crystallization, followed by rapid formation of micro-grains surrounding the nanocrystals. It has been suggested that the growth of micro-grains progresses via supercooled liquid Sn at the amorphous/crystalline interface. The resultant GeSn grains with a size of a few micrometers contained ∼15 at. % Sn, much larger than the solubility limit of Sn in Ge (∼1 at. % Sn). [ABSTRACT FROM AUTHOR]

We investigate how varying molecular topology of polymers influences crystallization in thin polymer films. In particular, we simulate linear and star polymers of fixed mass having a progressively increasing number of arms (f ≤ 16) in a system where the linear polymer exhibits crystallization in a thin film geometry, but no apparent crystallization in the corresponding bulk material. The degree of crystallization of the polymer film at long times decreases progressively with increasing f, and no crystallization is observed beyond f = 8. Crystallization for smaller values of f develops as a sigmoidally shaped wavefront initiating from the supporting crystalline interface. We suggest that large shape fluctuations and the competition of length scales of star polymers with high f lead to inhibited crystallization. [ABSTRACT FROM AUTHOR]

2H MoTe2 (molybdenum ditelluride) has generated significant interest because of its superconducting, nonvolatile memory, and semiconducting of new materials, and it has a large range of electrical properties. The combination of transition metal dichalcogenides (TMDCs) and two dimensional (2D) materials like hexagonal boron nitride (h-BN) in lateral heterostructures offers a unique platform for designing and engineering novel electronic devices. We report the fabrication of highly conductive interfaces in crystalline ionic liquid-gated (ILG) field-effect transistors (FETs) consisting of a few layers of MoTe2/h-BN heterojunctions. In our initial exploration of tellurium-based semiconducting TMDs, we directed our attention to MoTe2 crystals with thicknesses exceeding 12 nm. Our primary focus centered on investigating the transport characteristics and quantitatively assessing the surface interface heterostructure. Our transconductance (gm) measurements indicate that the very efficient carrier modulation with an ILG FET is two times larger than standard back gating, and it demonstrates unipolarity of the device. The ILG FET exhibited highly unipolar p-type behavior with a high on/off ratio, and it significantly increased the mobility in MoTe2/h-BN heterochannels, achieving improvement as one of the highest recorded mobility increments. Specifically, we observed hole and electron mobility values ranging from 345 cm2 V−1 s−1 to 285 cm2 V−1 s−1 at 80 K. We predict that our ability to observe the intrinsic, heterointerface conduction in the channels was due to a drastic reduction of the Schottky barriers, and electrostatic gating is suggested as a method for controlling the phase transitions in the few layers of TMDC FETs. Moreover, the simultaneous structural phase transitions throughout the sample, achieved through electrostatic doping control, presents new opportunities for developing phase change devices using atomically thin membranes. [ABSTRACT FROM AUTHOR]

During subduction, metamorphic dehydration reactions in the downgoing slab release fluids, generating fluid overpressure. It has been suggested that fluid is driven to flow upward by buoyancy, but a sufficiently high permeability allowing formation of a fluid percolation network is required. Traditionally, fluid percolation has been identified based on the textural equilibrium assumption by measuring the dihedral angle at the triple junction of grains. According to this theory, grain boundaries generally cannot be infiltrated by fluid, and only the grain edge can form a fluid flow channel. We argue that this theory is insufficient because we have found that water from fluid can be adsorbed into the crystalline interface, that is, a layered mineral interlayer, a crack, or a grain boundary. The high pressure in a subducting slab drives water adsorption into the crystalline interface, forming a low‐dimensional fluidic phase, and thus fluid percolation is achieved. Because water adsorbed in the interface is fluidic, water diffusion drives fluid transport in the subducting slab. Due to water adsorption, fluid overpressure at the dehydration front may release, so that dehydration embrittlement may be excluded. Stable water adsorption in the subduction‐slab conditions is determined here by combining molecular dynamics simulations and thermodynamic calculations. Analysis based on simulations shows that water adsorption requires crystalline surfaces which do not form hydrogen bonds well. Plain Language Summary: Fluids are released during dehydration reactions of hydrous minerals in downgoing slabs. As the density of fluid is smaller than that of rock, buoyancy drives the upward flow of the fluid. However, if fluid domains are isolated rather than well connected in porous rock, this fluid flow may be inhibited. The traditional textural equilibrium theory used to determine whether there is percolation of the fluid network excludes the infiltration of fluid into grain boundaries. However, here, we show that under high pressure, water from fluid can be adsorbed into a crystalline interface, forming a fluidic phase, and thus facilitating fluid percolation. The crystalline interface we study here is the interlayer of layered minerals, but in analogy, the understanding provided in this study can be generalized to other crystalline interfaces, for example, cracks or grain boundaries. If the crystalline surfaces do not form hydrogen bonds well, water adsorption can occur. Fluid migration in a slab is mediated by water within the crystalline interface. Water adsorption into crystalline interface may also play the role of transmitting earthquake‐triggering fluid overpressure, so that brittle failure may be excluded. Stable adsorption of water is identified here with a thermodynamic study based on atomic‐scale simulations. Key Points: Water from fluid can be adsorbed into crystalline interfaces under a high pressure, becoming a fluidic low‐dimensional phaseThis low‐dimensional phase facilitates fluid percolation and migration in a subducting slabWater adsorption into crystalline interface releases fluid overpressure, so that dehydration embrittlement may be excluded [ABSTRACT FROM AUTHOR]

Phase-Change Materials (PCMs) are widely applied in dynamic optical modulation due to the dramatic changes in their complex refractive index caused by temperature variation. As the functionality varies, the application of a single PCM cannot meet the compact, efficient and broadband needs of optical modulators. In this work, we combine vanadium dioxide (VO2) and a chalcogenide (Ge2Sb2Te5 (GST) or In3SbTe2 (IST)) to obtain a VO2–GST/IST multiple-stack film that is optimized by a genetic algorithm. This film has a wide spectrum and high modulation properties with three self-switchable modes varied by temperature, including transmission, absorption and reflection. The optimal results are an average normal transmittance, absorbance, and reflectance of 0.76, 0.91, 0.86 in 3–5 μm and 0.72, 0.90, 0.90 in 8–14 μm under different temperature ranges. The film enhances the transmission and absorption properties due to the formation of anti-reflective coating and Fabry–Perot resonance. Compared with GST, the film maintains high reflectance due to the metal-like interface reflection of crystalline IST, which exhibits metallic properties. For different polarization states, the film demonstrates great directional insensitivity when the incidence angles vary from 0° to 60°. The designed self-adaptive multistage infrared radiative thermo-optic modulator has promising implications for optical fuse, fiber-optic communication and energy storage fields. [ABSTRACT FROM AUTHOR]

Raman spectroscopy has proven its effectiveness as a highly informative and sensitive method for the nondestructive analysis of layered nanostructures and their interfaces. However, there is a lack of information concerning the characteristic phonon modes and their activity in Si/SiO2 nanostructures. In order to overcome this problem, the phonon states and Raman spectra of several Si/SiO2 superlattices (SL) with layer thicknesses varied within 0.5–2 nm are studied using DFT-based computer modeling. Two types of structures with different interfaces between crystalline silicon and SiO2 cristobalite were studied. A relationship between the phonon states of heterosystems and the phonon modes of the initial crystals was established. Estimates of the parameters of deformation potentials are obtained, with the help of which the shifts of phonon frequencies caused by elastic strains in the materials of the SL layers are interpreted. The dependence of intense Raman lines on the SL structure has been studied. Several ways have been proposed to use this information, both for identifying the type of interface and for estimating the structural parameters. The obtained information will be useful for the spectroscopic characterization of the silicon/oxide interfaces. [ABSTRACT FROM AUTHOR]

The 5d two‐dimensional electron gas (2DEG) based on KTaO3 (KTO) exhibits a lot of exotic properties such as stronger spin‐orbit coupling (SOC) and higher superconductivity transition temperature than those of SrTiO3 (STO)‐based 3d 2DEGs, whereas it has much lower electron mobility. Herein, the property of the 5d 2DEGs is investigated including the carrier mobility and Rashba SOC by interfacing both amorphous and crystalline STO with the crystalline KTO. Metallic 2DEGs are achieved at both interfaces of amorphous and crystalline STO‐capped KTO. Notably, the amorphous STO/KTO heterointerface has a larger carrier concentration and higher Hall mobility than the crystalline STO/KTO counterparts at low temperatures, which stems from two kinds of carriers. In contrast, the 5d 2DEG formed at the crystalline interface exhibits much stronger Rashba SOC as revealed through magnetotransport measurement. The deduced maximum strength of Rashba SOC and spin‐splitting energy are ≈8.56 × 10−12 eV m and ≈33.52 meV, respectively. Our results provide new insights on designing on‐demand properties of KTO‐based conducting interfaces. [ABSTRACT FROM AUTHOR]

The oxide-semiconductor interface is a key element of MOS transistors, which are widely used in modern electronics. In silicon electronics, SiO2 is predominantly used. The miniaturization requirement raises a problem regarding the growing of heterostructures with ultrathin oxide layers. Two structural models of interface between crystalline Si and cristobalite SiO2 are studied by using DFT-based computer modelling. The structures of several Si/SiO2 superlattices (SL), with layer thicknesses varied within 0.5–2 nm, were optimized and tested for stability. It was found that in both models the silicon lattice conserves its quasi-cubic structure, whereas the oxide lattice is markedly deformed by rotations of the SiO4 tetrahedra around axes perpendicular to the interface plane. Based on the analysis of the calculated total energy of SLs with different thicknesses of the layers, an assessment of the interface formation energy was obtained. The formation energy is estimated to be approximately 3–5 eV per surface Si atom, which is close to the energies of various defects in silicon. Elastic strains in silicon layers are estimated at 5–10%, and their value rapidly decreases as the layer thickens. The elastic strains in the oxide layer vary widely, in a range of 1–15%, depending on the interface structure. [ABSTRACT FROM AUTHOR]

Hydrogen evolution reaction (HER) is an important process in electrochemical energy technology, and efficient electrocatalysts are of great significance for renewable and sustainable energy conversion. Here, we report a facile hydrothermal and heat treatment process to synthesize a series of Pt-based nanocapsules (NCs) as an effective hydrogen evolution catalyst. The Pt/TeO x NCs exhibit excellent HER activity in an alkaline medium. The Pt/TeO x NCs only need the overpotential of 33 mV to achieve the current density of 10 mA cm−2, and the Tafel slope was as low as 29 mV dec−1, which was even better than that of commercial Pt/C. Detailed experimental characterizations demonstrate that the interface between the crystalline Pt/amorphous TeO x and the strong electron transfer contribute to alkaline HER activity. This work opens up a new direction for the preparation of efficient catalysts for electrocatalytic reactions or other conversion filed. The Pt/TeO x NCs with Pt clusters anchored on TeO x amorphous substrate were successfully prepared. The overpotential was only 33 mV at the current density of 10 mA cm−2 and the Tafel slope was as low as 29 mV dec−1, which was significantly better than that of commercial Pt/C. The excellent HER performance may originate from the strong electronic interaction and optimized binding energy for intermediate. [Display omitted] • The Pt/TeO x NCs with Pt clusters anchored on TeO x amorphous substrate is reported. • The Pt/TeO x NCs exhibit excellent HER activity with low overpotential in 0.1 M KOH. • The presence of Pt-TeO x interface is conducive to improving alkaline HER activity. [ABSTRACT FROM AUTHOR]

OER (oxygen evolution reaction) is a critical reaction in several storage and conversion systems for renewable and clean electrochemical energies, including solar fuel devices, metal–air batteries, as well as regenerative fuel and water splitting cells. Regarding the shortcomings of OER, apart from the sluggish kinetics and high reaction overpotential, the reaction rate and overpotential are difficult to be optimized simultaneously. Herein, a novel hierarchical particle–sheet-structured Fe-doped NixP electrocatalyst is developed, which presents abundant interfaces between crystalline particle and amorphous sheet. The OER overpotential is reduced to 204 mV at 20 mA cm−2 current density, while it is reduced to 225 and 231 mV at 100 and 300 mA cm−2, respectively. The Fe-doped NixP electrocatalyst also shows fast reaction kinetics, whose Tafel slope is a remarkable 25 mV dec−1. For an electrolytic cell whose cathode and anode are Pt/C/NF and Fe–NixP/NF, respectively, a mere 1.446 V voltage is necessary to drive a 10 mA cm−2 current density for achieving overall water-splitting property. Notably, it also works stably at considerably high current densities of 500 and 1000 mA cm−2, representing high potential for commercial applications. [ABSTRACT FROM AUTHOR]

The contact of heterogeneous materials with different atomic structures and concentrations becomes omnipresent in modern materials. The differences across the interface introduce various gradients that could alter thermodynamic and kinetic behaviors of the materials. Here, we report a spontaneous melting of the interface formed by a crystalline metal and an amorphous solid at the temperature below their respective equilibrium melting temperatures. The transformation can even become continuous with disappearance of all known features of the first-order melting transition. We show that the change in the nature of melting in the interface region is caused by random disordering induced by interdiffusing atomic elements or impurities in the crystalline phase and the presence of a strong concentration gradient constrained by the sample geometry. [ABSTRACT FROM AUTHOR]

The modifying influence of aluminium phosphide to the morphology of primary Si and eutectic Si was investigated in hypereutectic Al-20Si alloys via adding Al-Cu-P master alloy (0.5, 1, 20 wt.%). Microstructural results showed when Al-Cu-P addition from 0 to 0.5%, primary Si phase decreases and eutectic Si phase size remains invariable; when addition higher than 0.5%, primary Si phase keeps invariable, eutectic Si phase size increases. To prove the nucleation effect of AlP on Si phase, interfacial properties of Si/AlP interface were investigated using first-principles calculations. Results showed the AlP(100)/Si(100) interface energy is between −1.45 J/m2 and −1.38 J/m2 for Al-terminated and P-terminated AlP model, both is much smaller than liquid Si/crystalline Si interface (0.34 J/m2), consolidates that AlP particles possess strong nucleation potency for Si phases. Therefore, the modifying influence of AlP to the morphology Si phase is well clarified as a function of AlP content in Al-20Si alloys. [ABSTRACT FROM AUTHOR]

The oxidation resistance and tribological behavior of CrAlN/SiN x multilayer films with different interface structures were investigated. The multilayer film exhibited better oxidation resistance than the monolithic CrAlN film after oxidation at 900 °C and 1000 °C for 10 h. The crystalline SiN x sublayer was beneficial to oxidation resistance at 900 °C in contrast to the trend observed after oxidation at 1000 °C. The stacking faults generated in the multilayer film were induced by the oxidation of SiN x. The diffusion mechanism changed from the outward diffusion of cations to an inward diffusion of anions when the temperature was increased to 1000 °C. The multilayer film with a crystalline interface exhibited lower coefficient of friction (COF) and better tribological properties than the CrAlN film and multilayer with an amorphous interface. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Co-Mn oxide catalyst with rich amorphous/crystalline interfaces is prepared. • CMO-400 with a/c interfaces shows high catalytic activity for C 3 H 8 oxidation. • A/c interfaces endow abundant oxygen vacancies and good reducibility. • Construction of a/c micro interfaces is a novel defect engineering strategy. Cobalt-manganese (Co-Mn) composite oxides show high potential for the catalytic oxidation of volatile organic compounds (VOCs). However, the low defect content and poor oxygen mobility of perfect spinel structure crystalline always make it difficult to effectively activate C–H bonds of propane. Here, the catalyst with rich amorphous MnO x /crystalline Co 3 O 4 interfaces was prepared, and the catalytic combustion activity for propane was determined. The rich amorphous/crystalline interfaces CMO-400 (i.e. Co-Mn oxide calcined at 400 °C) catalyst exhibited the best catalytic activity for propane with T 90 of 200 °C among all bimetallic Co-Mn oxides. Various characterizations and corresponding results have demonstrated that the abundant amorphous/crystalline interfaces could improve the catalytic performances, attributed to high oxygen vacancy concentration, low temperature reducibility, weak Mn−O bond strength, and good surface lattice oxygen mobility. It is noteworthy that the interface engineering of amorphous/crystalline is an effective strategy in VOCs catalytic oxidation. [ABSTRACT FROM AUTHOR]

Magnetron sputtering technology is employed to deposit WC layer with an amorphous/crystalline interface on a Ni/Cu/CF submicron rod array, and the constructed catalyst can be operated for over 10,000h for HER. [Display omitted] • Multi-stage tandem heterostructures are successfully constructed. • Magnetron sputtering makes scalable fabrication possible. • Amorphous/crystal interface optimizes electro-structure to enhance activity. • Involvement of Ni layer allows the ultra-long durability of over 10,200 h. • Ultralow cell voltage indicates industrial application perspectives. The creation of catalysts with rational structures is impressive for the achievement of highly efficient H 2 production. Nevertheless, the design of electrocatalysts with high reaction activity and long-term durability presents a significant challenge. This study details the fabrication of a unique multilayer tandem catalyst, constructed with an amorphous-crystalline (A-C) heterostructure A-C-WC/Ni/Cu submicron rod array, which was supported on copper foam through a low-cost in-situ growth/electrodeposition/magnetron sputtering approach. The hierarchical A-C-WC/Ni/Cu demonstrates a low overpotential of 105 mV for the hydrogen evolution at a current density of 100 mA cm−2, and it even endures for over 10,000 h at an industrial current density of 500 mA cm−2 in a 1 M KOH solution. This indicates a significant potential in an anion exchange membrane (AEM) electrolyzer. Theoretical calculations confirm the optimized adsorption energies and fast water-splitting kinetics. Additionally, the cell that was assembled with NiCoS x -0.4 yielded low cell voltages of 1.563 and 1.595 V while achieving high current densities of 1000 and 2000 mA cm−2 under industrial conditions (6 M KOH, 65 °C). The engineering of multiple heterostructure strategies presents a promising route towards the large-scale generation of hydrogen. [ABSTRACT FROM AUTHOR]

• Tensile deformation of lamellar γ-TiAl alloy is investigated by MD simulation. • PT interface has stronger release of strain energy to retard crack extension. • RB interface retard and resist crack extension by blunting crack tip. • Temperature suppresses dislocation propagation while strain rate is opposite. • FCC-to-BCC phase transition occurs at high strain rate and low temperature during the incipient plasticity. Crystalline interface plays a significant role in strengthening lamellar γ-TiAl alloys through reconciling the strength and ductility. Herein, the effects of temperature and strain rate on the tensile deformation of three lamellar γ-TiAl interface models are investigated by molecular dynamics simulations. The three interfaces, pseudo twin (PT), rotational boundary (RB), and true twin (TT), exhibit different tensile responses due to the different interface effects: TT interface only acts as a barrier of dislocation traversing to facilitate crack extension; PT interface acts as both dislocation barrier and emission source and has a stronger release of strain energy than TT interface, retarding the crack extension; RB interface can retard and resist crack extension due to the blunting and deflection of the crack tip and the best interface geometry compatibility. The defect evolution indicates that the elevated temperature suppresses dislocation propagation at low strain rate, while the high strain rate causes small lamellar stacking faults and slit-shaped holes along tensile direction at low temperature. In addition, the dual conditions of high strain rate and low temperature induce the phase transition from FCC to BCC and then BCC to HCP. These findings provide a specific insight to understand the atomistic mechanism of interface-mediated deformation. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D/3D integrated electrode with ample amorphous/crystalline interface is prepared. • The unique structures effectively repel chloride without blocking active sites. • CoNi-LDH/FeSe electrode shows superior OER performance in alkaline seawater. • This work achieves high activity, stability and selectivity for seawater OER. The superior electrocatalysts for seawater oxygen evolution reaction (OER) require fast kinetic to promote reactant (OH−) transport and adsorption, and to optimize oxygenated intermediates (O* and OOH*) adsorption, but also high corrosion resistance by impeding Cl− adsorption under harsh seawater conditions, while the incomprehensive design greatly hinder the system advancement at high current densities. Herein, we propose orderly incorporating amorphous FeSe nanosheets as the dynamic anti-corrosion layer to reinforce charge redistribution of CoNi layered double hydroxide (LDH) nanosheets array and create favorable microenvironments. The ordered two-dimensional/three-dimensional structure prepared by novel non-equilibrium electrodeposition strategy allows amorphous FeSe component not only to activate CoNi-LDH for promoting OH− adsorption, optimizing oxygenated intermediates adsorption and increasing Cl− adsorption energy, but also repel Cl− by dynamic polyanion layer without blocking active sites, thus affording effective seawater OER with low overpotential, excellent stability and high selectivity at high current densities. The integrated CoNi-LDH/FeSe electrode delivers a small overpotential (338 mV at 500 mA cm−2) and possesses outstanding stability and selectivity during a 500-hour durability test at 500 mA cm−2 in alkaline seawater. [ABSTRACT FROM AUTHOR]

The corrosion resistance to calcium‑magnesium‑aluminum-silicate (CMAS) is a key property affecting the long-term durability of thermal barrier coatings (TBCs). Meanwhile, rare-earth hafnates are considered promising TBC candidates due to their low thermal conductivity and suitable thermal expansion coefficients. Thus, this study explores the CMAS corrosion resistance of Gd 2 (Hf 0.7 Ce 0.3) 2 O 7 (GH7C3) ceramic material under different conditions and compares it with the binary system Gd 2 Hf 2 O 7 (GH) ceramic material. The findings indicate that GH7C3 can react chemically with CMAS and rapidly form a dense apatite crystalline layer at the interface between GH7C3 ceramic and CMAS, providing excellent CMAS resistance. Furthermore, the composition of the remaining CMAS melt Furthermore, the composition of the remaining CMAS melt undergoes compositional changes upon interaction, ultimately forming spinel in Mg and Al-enriched regions. In the meantime, CeO 2 can promote the rapid formation of apatite crystals, significantly enhancing the CMAS resistance of GH7C3 to CMAS at high temperatures compared to GH. • The Gd 2 (Hf 0.7 Ce 0.3) 2 O 7 (GH7C3) exhibited excellent resistance to CMAS corrosion. • Under the attack of CMAS, the Ce element in GH7C3 can promote the rapid crystallization of Gd-apatite. • In the GH7C3/CMAS system, apatite crystals can form a dense layer that effectively blocks further corrosion by CMAS. [ABSTRACT FROM AUTHOR]

Amorphous structure shows more catalytic active sites but poor conductivity towards oxygen evolution reaction (OER). Herein, we fabricated a novel three-dimensional (3D) self-supported NiFe layered double hydroxides (LDH) catalytic material with amorphous/ crystalline interface, aiming to obtain both excellent catalytic activity and conductivity. This homogeneous hierarchical structure exhibits a high catalytic activity and robustness, giving the industrially required current density of 1000 mA cm−2 at an ultralow overpotential of 359.8 mV with 240-hour stability in 1 M KOH. In-situ electrochemical tests reveal that the amorphous/crystalline interface boosts the intermediates evolution and OER kinetics, which might be ascribed to considerable active sites and fast charge transfer. Moreover, the 3D structure has unique superhydrophilicity and superaerophobicity, which can further accelerate the electrolyte penetration, facilitate the bubbles desorption from the electrode, enhance mass transport, and thus improve OER performance at large current densities. This work provides a feasible way to develop high-performance electrocatalytic material via constructing homogeneous amorphous/crystalline interface. • Amorphous/crystalline NiFe LDH heterostructure was successfully synthesized. • Heterostructure interface boosts the OER activity and stability of NiFe LDH. • Catalyst yields a low overpotential of 359.8 mV to drive 1000 mA cm-2 in 1 M KOH. • Catalyst exhibits 240-h stability at 1000 mA cm-2 with retention rate of 98 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • The initial stages of the interdiffusion in the PMMA/PVDF system has been investigated by STEM-EDX/EELS, with the help of Raman technique. • The crystallization of PVDF exhibited a nonnegligible impact on the interdiffusion across the amorphous/crystalline interface of PMMA/PVDF. • The activation energy for the interdiffusion across the interface of PMMA/PVDF was calculated to be 51.0 kJ/mol by STEM plus EDX/EELS. Interdiffusion across the interface of poly(methyl methacrylate)/poly(vinylidene fluoride) (PMMA/PVDF) was investigated thoroughly by scanning transmission electron microscopy (STEM) plus electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray spectrometry (EDX) and further with the assistance of laser-Raman spectroscopy. The factors of the annealing temperature and the time on the interfacial widths and the concentration profiles of PMMA and PVDF across the interface of PMMA/PVDF have been considered in detail. It was found that the concentration profiles of PMMA and PVDF were determined by the crystallization of PVDF, especially at the high annealing temperature (220 °C) in the PMMA part of the interface. Under the influence of the PVDF crystallization, the concentration profiles of F (from PVDF) and O (from PMMA) monitored by STEM-EDX/EELS changed gradually from parabola-shape to linear-shape in the PMMA part. The activation energy for the interdiffusion across the interface of PMMA/PVDF was calculated to be 51.0 kJ/mol, lower than the other reported pairs like poly(vinyl chloride)/poly(ε -caprolactone) (PVC/PCL) (69.8 kJ/mol) and poly(styrene- ran -acrylonitrile)/poly(methyl methacrylate) (SAN-29/PMMA) (175 ± 15 kJ/mol). [ABSTRACT FROM AUTHOR]

Extensive molecular dynamics simulations of xenon in two classes of zeolite crystal systems, one consisting of purely intra-crystalline space and the other with both intra- and inter-crystalline space are reported. The latter mimics a typical poly-crystalline sample of zeolite. Comparison of results from these two systems provides insights into the structure and dynamics in the presence of inter-crystalline space. The temperature, as well as the distance between the crystallites, has been varied. The density distribution and diffusivities calculated inside the poly-crystalline system show that the interfacial region between the crystal and the inter-crystalline region acts as a bottleneck for diffusion through the system. At lower temperatures, the particles are trapped at the interface due to the pronounced energy minima present in that region. With the increase in temperature, the particles are able to overcome this barrier frequently, and the transport across the inter-crystalline region is increased. A ballistic or superdiffusive motion is seen in the inter-crystalline region along all the axes except along the axis which has the inter-crystalline space. The transition time for ballistic to diffusive motion increases with the increase in the length of the inter-crystalline space. Velocity auto- and cross correlation functions exhibit strong oscillations and exchange of kinetic energy along directions perpendicular to the direction of the inter-crystalline space. These results explain why uptake and PFGNMRmeasurements exhibit lower values for diffusivity for the same system when compared to Quasi- Elastic Neutron Scattering. Thus, using molecular dynamics simulations, we were able to correlate the difference of diffusivity values measured using various experimental methods where these intercrystalline regions are common. [ABSTRACT FROM AUTHOR]

2D electron gases (2DEGs) formed at oxide interfaces provide a rich testbed for fundamental physics and device applications. While the discussion of the physical origins of this phenomenon continues, the recent discovery of oxide 2DEGs at non-epitaxial interfaces between amorphous and crystalline oxides provides useful insight into this debate. Furthermore, using amorphous oxides offers a low-cost route towards realizing 2DEGs for device applications. In this work, the band offsets of a simple model system of an amorphous-crystalline oxide interface are investigated. The model system consists of amorphous Al2O3 grown on single-crystalline (001) SrTiO3. X-ray photoelectron spectroscopy is employed to study the chemical states, bandgap, and band offsets at the interface. The density of ionic defects near the interface is found to be below the detection limit, and the interface is found to be insulating. Analysis of the relative band structure yields significant interfacial barriers, exceeding 1.05 eV for holes and 2.0 eV for electrons. The barrier for holes is considerably larger than what is known for related material systems, outlining the promise of using amorphous Al2O3 as an effective and simple insulator, an important building block for oxide-based field effect devices. [ABSTRACT FROM AUTHOR]