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Although widely studied experimentally in the 1990s, the structure and properties of low-dimensional or high-pressure phases of fullerenes have recently been re-examined. Remarkably, recent experiments have shown that transparent, nearly pure amorphous sp3-bonded carbon phases can be obtained by heating a C60 molecular crystal at a high pressure. With the additional aim of testing the ability of three classical carbon potentials reactive empirical bond order, environment-dependent interatomic potential, and reactive force-field to reproduce these results, we investigate the details of the structural transformations undergone by fullerene crystals over a wide range of pressures and temperatures. All the potentials tested show that the initial polymerization of fullerenes is accompanied by negative thermal expansion, albeit in slightly different ranges. However, more significant differences in structural and mechanical properties are observed in the amorphous phases, in particular the sp3 carbon fraction and the existence of layered amorphous carbon. Overall, these results indicate to which extent classical reactive potentials can be used to explore phase transitions over a wide range of pressures and temperatures. [ABSTRACT FROM AUTHOR]

Amorphous carbon nitride (a-CNx) films, prepared by reactive radio frequency magnetron sputtering, exhibit unique characteristics under visible light irradiation, referred to as photoinduced deformation. This phenomenon represents an energy conversion system wherein photon energy transforms into kinetic energy. The chemical bonding structure of a-CNx films was analyzed using near-edge x-ray absorption fine structure (NEXAFS) at the NewSUBARU synchrotron facility of the University of Hyogo, Japan. This analysis aimed to elucidate the mechanisms behind the photoinduced deformation observed in a-CNx films. Three variants of a-CNx films, displaying varying degrees of photoinduced deformation, were deposited using a graphite target and nitrogen gas under different deposition temperatures. The NEXAFS spectra of the a-CNx films with substantial photoinduced deformation showed changes under light irradiation from a Xe lamp (directed through an optical window within the NEXAFS chamber). Specifically, the peaks corresponding to the 1s to π* transition related to C—C and 1s to σ* transition related to C—N bonds exhibited high sensitivity to visible light irradiation. Simultaneously, the N K-edge spectra associated with the 1s to π* transition, attributed to the N—C bond, exhibited a slight intensity decrease. Conversely, the C K-edge spectrum in the a-CNx films displaying minimal photoinduced deformation remained unchanged under visible light irradiation. The N K-edge spectra maintained a consistent shape under both visible light and dark conditions. [ABSTRACT FROM AUTHOR]

Ge-Sb-Te (GST) alloys are leading phase-change materials for data storage due to the fast phase transition between amorphous and crystalline states. Ongoing research aims at improving the stability of the amorphous phase to improve retention. This can be accomplished by the introduction of carbon as a dopant to Ge2Sb2Te5, which is known to alter the short- and mid-range structure of the amorphous phase and form covalently bonded C clusters, both of which hinder crystallization. The relative importance of these processes as a function of C concentration is not known. We used molecular dynamics simulation based on density functional theory to study how carbon doping affects the atomic structure of GST-C. Carbon doping results in an increase in tetrahedral coordination, especially of Ge atoms, and this is known to stabilize the amorphous phase. We observe an unexpected, non-monotonous trend in the number of tetrahedral bonded Ge with the amount of carbon doping. Our simulations show an increase in the number of tetrahedral bonded Ge up to 5 at.% C, after which the number saturates and begins to decrease above 14 at.% C. The carbon atoms aggregate into clusters, mostly in the form of chains and graphene flakes, leaving less carbon to disrupt the GST matrix at higher carbon concentrations. Different degrees of carbon clustering can explain divergent experimental results for recrystallization temperature for carbon doped GST. [ABSTRACT FROM AUTHOR]

This paper explores the unintentional contamination of Surface-Enhanced Raman Scattering (SERS) substrates by ambient hydrocarbon contaminants and their contribution to SERS spectra. Previous studies have identified amorphous carbon as a potential complicating factor in data analysis in SERS experiments, although its origin has been elusive. Our work showed that ambient hydrocarbon contamination and its decomposition products can be detected by SERS on a gold substrate. We propose that ambient air itself is a source of amorphous carbon contamination on SERS substrates. This understanding is crucial for the correct interpretation of SERS data and highlights the need for careful consideration of potential environmental contaminants in SERS analysis. [ABSTRACT FROM AUTHOR]

C-incorporated amorphous silica (a-SiOC) is expected to be a significant dielectric film for miniaturized semiconductor devices. However, information on the relationship among its composition, atomic structures, and material properties remains insufficient. This study investigated the dependence of the elastic modulus on the C content in a-SiOC, employing a universal neural network interatomic potential to realize a high-accuracy and high-speed simulation of multicomponent systems. The relationship between elastic modulus and atomic network structures was explored by fabricating 480 amorphous structures through the melt-quenching method without predetermined structure assumptions. The bulk modulus increased from 45 to 60 GPa by incorporating 10% C atoms under O-poor conditions and 20% C atoms under O-rich conditions, respectively. This result is attributed to the formation of denser crosslinking atomic network structures. In particular, the C atoms bonded with the Si atoms with higher coordination under O-poor conditions, whereas they tend to bond with O atoms under O-rich conditions, breaking the SiO2 network. Large C clusters precipitated as the C fraction was increased under O-rich conditions. Gas molecules, such as CO and CO2, were also generated. These results are consistent with reported ab initio calculation results of the formation energies of C defects and gas molecules in SiO2. The findings suggest that realizing O-poor conditions during deposition is crucial for fabricating stronger dielectric films. Therefore, this work contributes to understanding the fabrication of stronger dielectric films and elucidating the underlying mechanism of C cluster formation. [ABSTRACT FROM AUTHOR]

The tetrahedral amorphous carbon (ta-C) coatings are deposited on piston rings to improve the tribological property of the piston ring-cylinder liner system of the internal combustion engines. The deposition parameters are optimized by molecular dynamics simulation to reduce the cost of coatings' fabrication. The ta-C coatings with higher sp3 fraction, lower friction coefficient, and superior anti-wear properties are achieved by optimizing the incident energy and substrate temperature of carbon atoms. The second nearest-neighbor modified embedded-atom method potential and Tersoff potential are used to describe the interatomic interactions. The effects of the incident energy of the carbon atoms and substrate temperature on the deposition properties of the ta-C coatings are discussed. The numerical results show that the ta-C coatings with high sp3 fraction, high density, and good interface mixing are obtained, and the deposition properties of the ta-C coatings are improved. [ABSTRACT FROM AUTHOR]

A systematic review and meta-analysis of sputter yield data for xenon ions normally incident on graphite at energies below 2000 eV was undertaken to identify systematic errors, determine the best model parameter values to represent yield as a function of energy, quantify uncertainty, and determine if the data support differences in yields for different types of graphite. A critical examination of the 11 published data sets for high density graphite, pyrolytic graphite, and amorphous carbon showed that, in general, they were carefully controlled to minimize errors. The most significant quantifiable systematic errors were those caused by the neglect of doubly charged ions, chemical erosion, and the impact of secondary electron emission on ion flux measurements. The effects of gas uptake and outgassing on mass loss measurements and unrepresentative surface textures may have biased other experiments, but these effects could not be quantified. The semi-empirical Eckstein model for yield as a function of energy was fit to data for the three graphite types using a hierarchical Bayesian statistical model, producing recommended fit parameters and probability distributions representing uncertainty in yields. The results showed that differences in yield for high density graphite and pyrolytic graphite were not statistically significant. Apparent differences in yield for amorphous carbon disappeared when the single data set available for energies below 150 eV was corrected for reasonable values of double ion content. Recommended procedures to avoid systematic errors and additional experiments and modeling to fill in gaps in our understanding are included. [ABSTRACT FROM AUTHOR]

Carbon-doped Ge2Sb2Te5 (CGST) is a potential candidate in phase change random access memory (PCRAM) with superb thermal stability and ultrahigh cycle endurance. Direct observation of the microstructure evolution of CGST is desirable to uncover the phase transformation mechanism on the relationship of nucleation/crystalline behaviors of the crystalline phase at elevated temperatures and the pristine amorphous phase at room temperature. Here, we investigate the structural evolution of CGST using combined in situ techniques. Our in situ x-ray diffraction and ellipsometry results demonstrate that CGST exhibits a much higher phase transition temperature than undoped one. Temperature-dependent in situ transmission electron microscopy observations further reveal that carbon doping plays a critical role in tailoring the properties of GST by tuning the stochasticity of nucleation/crystallization, stabilizing amorphous and crystalline GST via isolating and refining the grain size at room temperature and elevated temperature. Our work provides detailed information for understanding the microscopic origin of crystallization kinetics of carbon-doped phase change materials toward high-performance PCRAM. [ABSTRACT FROM AUTHOR]

Direct bandgap group IV materials could provide intimate integration of lasers, amplifiers, and compact modulators within complementary metal–oxide–semiconductor for smaller, active silicon photonics. Dilute germanium carbides (GeC) with ∼1 at. % C offer a direct bandgap and strong optical emission, but energetic carbon sources such as plasmas and e-beam evaporation produce defective materials. In this work, we used CBr4 as a low-damage source of carbon in molecular beam epitaxy of tin-free GeC, with smooth surfaces and narrow x-ray diffraction peaks. Raman spectroscopy showed substitutional incorporation of C and no detectable sp2 bonding from amorphous or graphitic carbon, even without surfactants. Photoluminescence shows strong emission compared with Ge. [ABSTRACT FROM AUTHOR]

Direct bandgap group IV materials could provide intimate integration of lasers, amplifiers, and compact modulators within complementary metal–oxide–semiconductor for smaller, active silicon photonics. Dilute germanium carbides (GeC) with ∼1 at. % C offer a direct bandgap and strong optical emission, but energetic carbon sources such as plasmas and e-beam evaporation produce defective materials. In this work, we used CBr4 as a low-damage source of carbon in molecular beam epitaxy of tin-free GeC, with smooth surfaces and narrow x-ray diffraction peaks. Raman spectroscopy showed substitutional incorporation of C and no detectable sp2 bonding from amorphous or graphitic carbon, even without surfactants. Photoluminescence shows strong emission compared with Ge. [ABSTRACT FROM AUTHOR]

In proton exchange membrane fuel cells (PEMFCs), the interfacial contact resistance (ICR) of amorphous carbon (a-C) coated metallic bipolar plates (BPs) increased with the passage of time, thereby severely limiting their widespread application. The performance of a-C coated BPs was considerably influenced by interface-induced degradation, which in turn was highly sensitive to sp2/sp3, size of sp2 clusters, and compactness of a-C. These factors were closely linked to the underlying metal transition layers and dependent on the deposition temperature. Therefore, in order to elucidate the impact of interface structure on their performance, a series of a-C coatings with Cr transition layer were magnetron sputtered onto 316L stainless steel at temperatures ranging from room temperature (R.T.) to 400 °C. The results revealed that as the deposition temperature increased, the a-C coatings became more porous and exhibited columnar growth characteristics attributed to the hill-like interface structures of the Cr transition layer. Additionally, both the sp2 content and cluster size of a-C increased. Correspondingly, the initial ICR decreased from 2.89 Ω cm2 at R.T. to 1.62 Ω cm2 at 400 °C. Furthermore, in long-term corrosion tests, both the ICR after corrosion and metal ion concentrations in the corrosion solution rose rapidly. Notably, the a-C coating deposited at 100 °C showed the lowest corrosion current density of 5.81 × 10−4 μA/cm2 and the smallest increase rate (65.9%) of ICR after the long-term electrochemical corrosion test, owing to its high sp2 content and dense structure. • Sp2 cluster size of a-C films were separately controlled by deposition temperature. • Increasing sp2 clusters size significantly reduced the initial ICR of a-C films. • XRR analysis revealed the decrease in film compactness with temperature increment. • Loose structure deteriorated the corrosion resistance of a-C in simulated PEMFC environment. [ABSTRACT FROM AUTHOR]

As a kind of ultra-high temperature ceramic, TaC is widely used in aerospace field. In order to improve its high temperature oxidation resistance, SiC is usually added as a second phase. TaC-SiC nanocomposites prepared by precursor-derived ceramic method have the advantages of low pyrolysis temperature, small particle size and uniform phase composition. Some studies have used solid polycarbosilane (PCS) as the precursor of SiC. However, it has problems such as high cost and need to add solvent. In this work, TaC-SiC nanocomposites were prepared by precursor-derived ceramic method with polytantaloxane (PTO) and vinyl-containing liquid polycarbosilane (LPVCS) instead of PCS as raw materials after 2 h pyrolysis at 1600 °C. The obtained TaC-SiC nanocomposites have a particle size of about 200 nm and a grain size of 15–40 nm, wrapped by 1–2 nm amorphous carbon shells, which is beneficial to inhibit grain growth. By analyzing the oxidation mechanism of TaC-SiC nanocomposites, it was found that higher SiC content was conducive to antioxidant, because the SiO 2 protective layer formed by oxidation insulated O 2 diffusion. [ABSTRACT FROM AUTHOR]

An MgH2–anthraquinone carbonization product composite (denoted as MgH2–ACP composites) was successfully prepared through a hydrogenation combustion and mechanical ball-milling method using the original Mg powder to simultaneously achieve modification via in situ-formed amorphous carbon. The amorphous carbon derived from the combustion of carbonic compounds significantly enhanced the hydrogen-absorption and -desorption performances of MgH2. Results revealed that the onset decomposition temperature of the MgH2–ACP composite decreased from 638 K to 587 K in the dehydrogenation stage. Moreover, the MgH2–ACP sample delivered dehydrogenation capacities of 3.525 wt% at 598 K, whereas the as-milled MgH2 decomposed only 0.763 wt% at the same temperature. The activation energies calculated using Kissinger analysis in the dehydrogenation process of MgH2 were lowered by about 57.5 kJ mol−1. For the absorption kinetic measurements at 473 K, the MgH2-ACP sample could uptake about 4.629 wt% of H2 in 3200 s compared to 1.804 wt% taken up by the as-milled MgH2. The in situ-formed amorphous carbon and MgO were confirmed as the active species that contributed to the enhancement of hydrogen-storage properties of the composite. [ABSTRACT FROM AUTHOR]

Surface roughness control of end products is increasingly becoming significant, especially with the miniaturization trends in the semiconductor industry. Ultra-thin amorphous carbon (a-C) films offer a prime solution to optimize surface roughness due to their outstanding characteristics. In this study, hydrogenated a-C films are deposited on two-dimensional quartz plates and three-dimensional quartz molds to evaluate the growth mechanisms and changes in the surface roughness, which is supported by molecular dynamics simulations. Results reveal that surface roughness encounters multiple variations until it reaches stable values. These fluctuations are categorized into four different stages which provide a concrete understanding of various growing mechanisms at each stage. Different behavior of the atoms in the top layers is recorded in the cases of normal and grazing incidents of carbon atoms. Lower surface roughness values are obtained at low-angle deposition. Interestingly, surface smoothing is attained on the sidewalls of the nanotrench mold where the deposition occurs with high incident ion angles. [ABSTRACT FROM AUTHOR]

An MgH2–anthraquinone carbonization product composite (denoted as MgH2–ACP composites) was successfully prepared through a hydrogenation combustion and mechanical ball-milling method using the original Mg powder to simultaneously achieve modification via in situ-formed amorphous carbon. The amorphous carbon derived from the combustion of carbonic compounds significantly enhanced the hydrogen-absorption and -desorption performances of MgH2. Results revealed that the onset decomposition temperature of the MgH2–ACP composite decreased from 638 K to 587 K in the dehydrogenation stage. Moreover, the MgH2–ACP sample delivered dehydrogenation capacities of 3.525 wt% at 598 K, whereas the as-milled MgH2 decomposed only 0.763 wt% at the same temperature. The activation energies calculated using Kissinger analysis in the dehydrogenation process of MgH2 were lowered by about 57.5 kJ mol−1. For the absorption kinetic measurements at 473 K, the MgH2-ACP sample could uptake about 4.629 wt% of H2 in 3200 s compared to 1.804 wt% taken up by the as-milled MgH2. The in situ-formed amorphous carbon and MgO were confirmed as the active species that contributed to the enhancement of hydrogen-storage properties of the composite. [ABSTRACT FROM AUTHOR]

Room temperature gas sensing is crucial for practical devices used in indoor environments. Among various materials, metal oxides are commonly used for gas sensing, but their strong insulating properties limit their effectiveness at room temperature. To address this issue, many studies have explored diverse methods such as nanoparticle decoration or conductive support, etc. Here, we report the emergence of gas-sensing functionality at room temperature with improved CO gas selectivity on SnO2 nanoparticles through sequential steps by using amorphous carbon (a-C) support and PtOx decoration. The SnO2 decorated on amorphous carbon shows enhanced gas adsorption compared to inactive gas sensing on SnO2 decorated carbon support. The higher Vo site of SnO2 on a-C induces gas adsorption sites, which are related to the higher sp2 bonding caused by the large density of C defects. The ambiguous gas selectivity of SnO2/a-C is tailored by PtOx decoration, which exhibits six values of sensing responses (Rg/Ra or Ra/Rg) under CO gas at room temperature with higher selectivity. Compared to PtOx/a-C, which shows no response, the enhanced CO gas sensing functionality is attributed to the CO adsorption site on PtOx-decorated SnO2 particles. This report not only demonstrates the applicability of CO gas sensing at room temperature but also suggests a strategy for using SnO2 and carbon compositions in gas sensing devices. [ABSTRACT FROM AUTHOR]

Copper (Cu) is widely used as an industrial electrode due to its high electrical conductivity, mechanical properties, and cost‐effectiveness. However, Cu is susceptible to corrosion, which degrades device performance over time. Although various methods (alloying, physical passivation, surface treatment, etc.) are introduced to address the corrosion issue, they can cause decreased conductivity or vertical insulation. Here, using the nitrogen‐doped amorphous carbon (a‐C:N) thin film is proposed as a substrate on which Cu is directly deposited. This simple method significantly inhibits corrosion of ultrathin Cu (<20 nm) films in humid conditions, enabling the fabrication of ultrathin electronic circuit boards without corrosion under ambient conditions. This study investigates the origin of corrosion resistance through comprehensive microscopic/spectroscopic characterizations and density‐functional theory (DFT) calculations: i) diffusion of Cu atoms into the a‐C:N driven by stable C‐Cu‐N bond formation, ii) diffusion of N atoms from the a‐C:N to the Cu layer heading the top surface, which is the thermodynamically preferred location for N, and iii) the doped N atoms in Cu layer suppress the inclusion of O into the Cu lattice. By leveraging the ultrathinness and deformability of the circuit board, a transparent electrode and a crumpleable LED lighting device are demonstrated. [ABSTRACT FROM AUTHOR]

Owing to the adverse influences of irreversible oxidation, the development of MXene‐based materials, especially those with satisfactory performance and longevity for aqueous energy storage, continues to suffer severe challenges. Herein, the strategy of targeted passivation‐supported defect‐lock‐oxygen is conceived, whereby engineered the V2CTx material for controllable partial oxidation with enhanced regioselectivity. When the material works, inside the intrinsic defects, the outward diffusion of oxidation is confined by the Lewis bases around the defects, which allows for the controllable progress of oxidation. The defect‐locked oxygen oxidizes the exposed carbon, thus forming sufficient amorphous carbons for enhancing the capacitive‐type adsorption of K‐ions. Then the oxidized defects enabled the fast kinetics via the cross‐layer transport of K‐ions. Benefiting from the strategy, the electrode assembly V2CTx‐RTIL (V2CTx equipped with room temperature ionic liquid) exhibits high capacity, good rate capability, and ultra‐longevity compared with those of the MXene materials so far reported. This work presents the first strategy of targeted passivation‐supported defect‐lock‐oxygen for high‐rate capability and super long‐cycling aqueous K+ storage and hopefully would provide the inspiration for the future design of novel electrodes. [ABSTRACT FROM AUTHOR]

In carbon allotropes, interfacial engineering of various sp2 nanocarbon building blocks has shown great promise in designing and fabricating creative nanocarbon assemblies with novel structural and functional properties. Here, a robust, flexible, metal‐like heterostructured carbon nanotube (CNT) film formed of amorphous graphene nanosheets (AGNs) on CNT networked film is demonstrated, presenting a sp3‐sp2 dominated interfacial heterostructure. Extensive characterization reveals that AGN exhibits a complete absence of long‐range periodicity with twisty six‐member rings. Such 2D graphene mailed 1D CNT structure endows the heterostructured carbon nanocomposite film with a combination of unique properties, including surface nano‐flattening (flatness fourfold of the raw CNT film), excellent anti‐wear performance, greatly enhanced modulus (enhanced by 400%), hardness (enhanced by 300 times), and conductivity (enhanced by 270%). Unlike conventional carbon‐based materials, such flexible films show distinct substantial deformability and rapid resilience over wide temperatures (−196–≈1300 °C), which facilitate the design of new‐concept lightweight high‐temperature resistant and shape‐transformable materials for advanced aerospace applications under extreme conditions. [ABSTRACT FROM AUTHOR]

Hydrogen has a strong effect on the tendency of fuels to produce soot. The aim of this study is to investigate the effect of hydrogen addition on the formation of soot and its structural evolution in ethylene/oxygen inverse diffusion flames. Laser spectroscopy was used to measure the spatial distribution of soot and Raman spectroscopy was utilized to characterize the nanostructure of soot. Additionally, the influence of hydrogen addition on the soot formation pathway was analyzed using ReaxFF molecular dynamics simulations. The results indicate that increasing hydrogen addition (α) progressively delays soot formation and narrows the flame radius. At 40% hydrogen, soot peak reduction was approximately 64.7%. Raman spectra revealed an increase in both graphite particle size and amorphous carbon content during soot growth. During the evolution of soot nanostructures, the initial particles dominated by sp carbon chains are gradually reorganized to form sp2 aromatic carbon structure, which is consistent with the simultaneous increase of soot concentration and graphite crystal size. It is worth noting that the crystal size of these graphite structure particles is concentrated in the range of 1.6–2.3 nm, indicating that they are in the transition stage from amorphous to microcrystalline. However, at the flame's end, both particle size and amorphous carbon content decreased simultaneously, attributable to oxidation by OH radicals. The study confirms the influence of soot formation and oxidation processes on nanostructures within flames. Raman spectroscopy also indicated a nonlinear change in soot oxidation reactivity along the axial direction of the flame, initially governed by gradual graphitization as flame temperature rises. Molecular dynamics simulations elucidated the nucleation and growth mechanisms of initial soot from polycyclic aromatic hydrocarbons (PAHs). These simulation results show that the increase of hydrogen content in the gas phase reduces the aggregation ability of polycyclic aromatic hydrocarbons and delays the formation of initial soot particles (C41+). With the growth of soot, its morphology gradually evolved from the initial dense, curved, and rotating spindle to a planar structure. The main chemotactic effect of this hydrogen participation is to hinder the dehydrogenation reaction of unsaturated hydrocarbons (H + C m H n → C m H n-1 + H 2), thereby inhibiting the formation of soot precursors, resulting in a decrease in the overall soot concentration. • The microstructure changes of soot in different regions of flame were obtained. • The effect of increasing hydrogen concentration on initial soot generation was obtained. • The effect of hydrogen doping on the morphology change and reaction path of soot formation was obtained. • The main factors affecting soot formation by hydrogen mixing were obtained. [ABSTRACT FROM AUTHOR]

Amorphous carbon is a promising candidate as an energy storage material. In this paper, we performed an X-ray total scattering measurement, RMC modeling, and persistent homology analysis for amorphous carbon samples fabricated at two different heat treatment temperatures. According to the analysis of the nearest-neighbor carbon atoms and their angular histogram, the sample treated at higher temperature shows higher connectivity between carbon atoms than that treated at lower temperature. Furthermore, topological data analysis (persistent homology, PH) reveals quantitative results that relate ring structure and the connectivity between carbon atoms. [ABSTRACT FROM AUTHOR]

In the past decades, the rapid depletion of non‐renewable energy sources has caused growing energy crisis and increasing emissions of carbon dioxide (CO2), which aggravates global warming and catastrophic climate change. Electrocatalysis is regarded as an effective method for consuming atmospheric CO2 and simultaneously alleviating the energy problem by converting CO2 into high value‐added chemicals. Amorphous nanomaterials with long‐range disordered structures possess abundant highly unsaturated atomic sites and dangling bonds on their surfaces, thus providing a large number of active sites, and show unique electronic structures compared to their crystalline counterparts due to the distinct atomic arrangements. Therefore, amorphous nanomaterials are recently demonstrated as highly efficient catalysts for diverse electrocatalytic reactions, including electrocatalytic CO2 reduction reaction (CO2RR). Here the rational synthesis and electrocatalytic performance of newly emerging amorphous nanomaterials will be outlined for electrocatalytic CO2RR. Importantly, the intrinsic merits of these amorphous catalysts in CO2RR processes will be summarized and highlighted. Finally, these perspectives on the remaining challenges and some potential future directions in this emerging field will also be provided. [ABSTRACT FROM AUTHOR]

The mechanical property is one of the most important properties of a material and is determined by the atomic-scale structure. It is thus crucial to establish the theoretical model for the prediction of materials' mechanical properties, benefiting the material design. In our previous work, we proposed an atomic-scale structure-based model for predicting the Young's modulus of hydrogenated amorphous carbon; however, the application range of this model is too narrow to be used practically for the materials development. Therefore, in this work, an extended prediction model of Young's modulus of materials with wide applicability is successfully constructed, based on the two important inherent properties of materials: one is effective coordination number (CN eff) evaluating how densely atoms are structured and the another one is effective bond stiffness (K eff) that is first proposed here and indicates how bonding types contribute the elastic properties. Through the high-throughput molecular dynamics simulations, the predictive model of Young's modulus (E) is determined as E = 3.37K eff (CN eff - 2.0)1.5. Then we demonstrate that this model is valid for a large variety of materials including both amorphous and crystalline structures, and the accuracy is proven by comparing with other work. Overall, this fundamental work may benefit the preparation, development, and utilization of new materials. [ABSTRACT FROM AUTHOR]

The rapid advancement of Internet of Things (IoT) technology and AI microchips has increased the demand for efficient and cost‐effective cooling solutions. However, traditional Bi2Te3‐based thermoelectric modules face the challenge of low abundance tellurium (Te). Although Te‐free modules using MgAgSb have been explored, they still suffer from a low price‐to‐performance ratio. To address these issues, this study investigates the development of alternative thermoelectric materials that are both cost‐effective and Te free. In this work, the potential of cost‐effective Te‐free alternatives is explored for thermoelectric applications by developing a high‐performance module composed of amorphous carbon‐modulated Mg3(Bi,Sb)2 and electron‐poor CdSb. The modules of CdSb/Bi2Te3 and CdSb/Mg3(Bi,Sb)2 demonstrate superior refrigeration performance, achieving a maximum temperature difference (ΔTmax) of 49.2 and 46 K, respectively. Notably, the material cost of CdSb/Mg3(Bi,Sb)2 module is only 5.5% of Te‐free modules built on MgAgSb, highlighting a significant economic advantage. This work provides a viable, ultralow‐cost approach to meet general refrigeration needs, thereby enhancing the practical value and application potential of thermoelectric materials. [ABSTRACT FROM AUTHOR]

One-dimensional core–shell hollow carbon nanofibers (HCNFs) have been synthesized by coaxial electrospinning, deacetylation and carbonization, which exhibit multi-surface properties that enhance electrolyte infiltration and facilitate ion/electron transport. The nitrogen-doped hard carbon outer shell compensates for the low conductivity of amorphous carbon, and the inner core carbon supports the stability of core–shell hollow structures. This unique structure ensures the accessibility of electrons/ions during electrochemical reactions and contributes to the superior rate performance of HCNFs. Ultimately, a high retention rate of 77% of the initial capacity value (0.1 A g−1) was demonstrated at a current density of 2 A g−1. The core–shell hollow structure designed in this work greatly optimizes the sodium transport dynamics. [ABSTRACT FROM AUTHOR]

Fe‐based sulfate materials have attracted much attention in the cathode of sodium‐ion batteries (SIBs) due to their low cost and high operating voltage, as well as possessing application prospects comparable to hard carbon in the anode based on Fe0/Fe2+/Fe3+ redox properties. However, the poor conductivity and the tendency to agglomerate have limited their further application. Herein, the study constructs a dual‐conductive structure that the Na2.31Fe1.72(SO4)3 particles with amorphous carbon in situ‐coated embedded in ketjen black (KB) conducting carbon networks (NFS/KB) via a solid phase ball‐milling strategy, which effectively enhanced inherent conductivity and electron transfer efficiency among particles of the Fe‐based sulphate. The NFS/KB can provide a reversible capacity of 92 mAh g−1 at 0.1 C and stable cycling stability at high current (85% retention after 500 cycles at 20 C) as cathode of SIBs. Surprisingly, as anode of SIBs, the NFS/KB delivers a rate performance (149 mAh g−1 at 10 C) that is superior to that of hard carbon. Notably, further application of the material to symmetric SIBs also achieves favorable results. This work effectively enhances the performance of Fe‐based sulphate materials in SIBs with a low‐cost carbon modification method, providing a new approach for the low‐cost symmetric SIBs. [ABSTRACT FROM AUTHOR]

Metallization of diamond with transition metals (TMs) has attracted much attention as they play an important role in the development of precision machining, high‐end thermal management, especially for electronic devices. However, it is found that the solid‐state reaction does not stop at the interface, potentially hampering interface engineering. To unleash the full potential of diamond devices, deeper reactions are investigated in monocrystalline intrinsic diamond metallized with Ti/Pt/Au ohmic contacts combing experiments and theoretical calculations. Apart from exhibiting TiC, graphite, TMs, and diamond nanocrystallites at the interface, a unique ion‐implanted‐like multilayered structure is observed at micrometer depth. TM atoms penetrate through diamond produce a buried amorphous carbon layer under the damaged diamond lattice. In addition, these theoretical calculations reveal that the structural amorphization is catalyzed by the incorporation of TM atoms through vacancy‐mediated diffusion, which induces the closure of the bandgap of the diamond. This facilitates carriers crossing the bandgap via impurity band conduction and promotes the formation of the ohmic contact. This study provides critical insight into the microscopic mechanisms of the metallization between diamonds and TMs and could facilitate the development of diamond‐based electronic devices with a tailored electronic property. [ABSTRACT FROM AUTHOR]

The TGA-EGA technique was used to study the influence of sulphanilic acid (SA) on the carbonisation process of the hybrid terpolymeric precursors composed of methacrylamide, divinylbenzene, and trimethoxyvinylsilane. The pristine polymers were impregnated with saturated solution of SA, dried, and carbonized at 600 °C under N2 atmosphere. The characteristic properties of both the pristine hybrid polymers and the resulting carbons were based on FTIR, Raman, and PXRD analyses, which revealed the materials were composed of amorphous polymeric or carbon phase interpenetrated by silica/silicate disordered network. The porosimetric analysis showed the resulted carbons possessed homogeneous supermicropores with the average pore width of 0.7 nm and reduced number of mesopores compared to pristine precursors. From the TGA results, it was followed that impregnated polymers decomposed in two stages, instead of one like pristine precursors did. Moreover, IDT of impregnated polymers was reduced by about 100 °C, and their Tmax was increased by 2–5.5 °C. Their decomposition proceeded slower by 22–37% that caused increase in efficiency of the process by 10–48%. The EGA showed the decomposition of the impregnated precursors started from the degradation of the amide groups, then SA destruction took place, followed by further decomposition of the polymer. The studies led to the conclusion that SA had the protective effect on the surface of the carbonized polymers. During impregnation and thermal treatment, SA produced a deposit in pores of the precursors. This resulted in narrowing of the pore width, delaying and slowing down the polymer thermal decomposition process, as well as increasing its efficiency. [ABSTRACT FROM AUTHOR]

Tetrahedral amorphous carbon (ta-C) film was deposited using the filtered pulsed cathodic arc deposition method. The ta-C structures deposited on high velocity oxygen fuel thermally sprayed steel beam substrates were investigated for piezoresistive properties under direct contact pressing. A load of up to 1.4 GPa was applied with point contact, with no detrimental influence on the material. The linear response for the strain applied homogeneously on the whole film surface and on the local portion of the film surface under a cylindrical contact was observed. A high gauge factor of the measured system of 305 was measured, showing the potential of the material as a good candidate for sensing applications on direct contact measurement devices. [ABSTRACT FROM AUTHOR]

Coconut coir-based porous carbon (CCPC) and magnetic iron (Fe) particle composite (CCPC/Fe) have been developed and characterized for potential applications in unmanned aerial vehicles (UAVs). Coconut coir was extracted from coconut husks and Fe compounds are impregnated to form CCPC/Fe. A comprehensive analysis was conducted, encompassing XRD analysis, revealing the presence of crystalline Fe particles and amorphous carbon, with broadened peaks and a crystalline size of 16.68 nm. Raman spectroscopy showed distinctive structural properties. UV-Vis spectroscopy exposed unique absorption peaks and SEM imaging confirmed the retention of porous structures and the successful integration of Fe particles. EDS analysis provided insights into the elemental composition, emphasizing the varying compositions of the sample. The VNA testing reflection loss value of -26 dB (2 mm thick sample) calculated from VNA testing indicated EM wave attenuation of > 99 %. These results underscores the potential of CCPC/Fe, making it an attractive candidate for advanced applications like EM wave attenuation in UAVs. The research contributes to materials science by offering a sustainable, cost-effective solution to enhance electromagnetic compatibility in UAVs, ensuring dependable and secure operation across diverse environments. [ABSTRACT FROM AUTHOR]

[Display omitted] The commercialization of Ni-based catalysts in CO 2 dry reforming of methane (DRM) suffers from their quick deactivation. Here, we reveal each reaction pathway for DRM based on the Ni catalyst composition and geometry under working conditions, through one working platform combining in situ high resolution Cs corrected environmental transmission electron microscopy and electron energy-loss spectroscopy coupled with mass spectroscopy. The formation of Ni 3 C has been found to inhibit the decomposition of CO 2 and CH 4 , and to promote the formation of onion-like carbon to encapsulate the Ni catalysts, leading to the deactivation of the Ni-based catalysts. Designing the suitable supports or promoters to keep the Ni surface structure under Ni-NiO cycle can drive the simultaneously amorphous carbon deposition-consumption cycle and minimise the coke formation. This research is not only for developing coke resistance Ni catalysts in the DRM, but also significant for investigating many catalysis challenges both in research and engineering. [ABSTRACT FROM AUTHOR]

NaTi2(PO4)3, as one of sodium superionic conductor (NASICON)-type anode materials, has been extensively concerned by researchers in Na-storage technologies due to their unique three-dimensional structure for Na+ insertion/deinsertion. However, the low conductivity of NaTi2(PO4)3 seriously hinders its electrochemical kinetics, which has been a major obstacle to further application. Herein, a facile strategy is proposed to synthesize carbon-incorporated NaTi2(PO4)3 nanoparticles on carbon cloth (NTP/C@CC) as a binder-free anode for aqueous sodium-ion hybrid capacitors (SIHCs). The amorphous carbon as a continuous conductive network can improve the electronic conductivity and restrict the particle growth of NaTi2(PO4)3. The small-sized NaTi2(PO4)3 nanoparticles embedded in the carbon network could increase the electrolyte/electrode interfacial area and shorten the Na+ transport path, resulting in increased electrochemical performance. Meanwhile, the carbon matrix can buffer the volume expansion during cycling and stabilize the structure of active materials. Consequently, the NTP/C@CC anode possesses a high specific capacity (0.416 mAh cm− 2 at 2 mA cm− 2), considerable rate capability (0.172 mAh cm− 2 at 30 mA cm− 2, 41.3% capacitance retention), and good long-term stability (83.2% capacitance retention after 5000 cycles at 30 mA cm− 2). In addition, an assembled SIHC device with P-doped porous carbon cloth (PPCC) as the cathode shows a capacity of 0.205 mAh cm− 2. The SIHC cell also acquires a superior energy density of 2.82 mWh cm− 3 and 81.5% capacity retention over 5000 cycles. This work may offer a viable way for constructing binder-free electrode materials for hybrid capacitors. [ABSTRACT FROM AUTHOR]

Micrometer‐sized silicon monoxide (SiO) is regarded as a high‐capacity anode material with great potential for lithium ion batteries (LIBs). However, the problems of low initial Coulombic efficiency (ICE), poor electrical conductivity, and large volume change of SiO inevitably impede further application. Herein, the vacuum thermal reduced SiOx with amorphous AlPO4 and carbon double‐coating layers is used as the ideal anode material in LIBs. The vacuum thermal reduction at low temperature forms fine silicon grains in the internal particles and maintains the external integrity of SiOx particles, contributing to mitigation of the stress intensification and the subsequent design of multifunctional coating. Meanwhile, the innovative introduction of the multifunctional amorphous AlPO4 layer not only improves the ion/electron conduction properties to ensure the fast reversible reaction but also provides a robust protective layer with stable physicochemical characteristics and inhibits the volume expansion effect. The sample of SiOx anode shows an ICE up to 87.6% and a stable cycling of 200 cycles at 1 A g−1 with an initial specific capacity of 1775.8 mAh g−1. In addition, the assembled pouch battery of 1.8 Ah can also ensure a cycling life of over 150 cycles, demonstrating a promising prospect of this optimized micrometer‐sized SiOx anode material for industrial applications. [ABSTRACT FROM AUTHOR]

The development of free‐standing and foldable electrodes with excellent electrochemical performance is paramount for flexible electronic devices. However, the silicon‐based free‐standing anodes lack a straightforward preparation process. Herein, we successfully designed a hierarchical Si@C/CNFs composite material by combining hydrothermal and electrospinning techniques, in which the carbon‐coated silicon (Si@C) is served as the primary nanostructure and carbon nanofibers (CNFs) from electrospinning are maintained as the network matrix, resulting in a free‐standing anode. Owing to the amorphous carbon coating on Si nanoparticles and the formation of a 3D network structure of CNFs, which tightly encases the primary Si@C nanostructure, the Si@C/CNFs electrode demonstrates exceptional conductivity and flexibility. This dual carbon‐layer structure further enhances kinetics and mitigates the volume expansion of Si nanoparticles. The Si@C/CNFs electrode exhibits a high specific capacity (1573 mAh g−1 at 0.1 A g−1), exceptional rate capability, and excellent cycling stability (78.5 % capacity retention after 100 cycles). Thus, Si@C/CNFs can be a promising material for the anode electrode in flexible lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Simultaneous achievement of lightweight, ultrahigh strength, large fracture strain, and high damping capability is challenging because some of these mechanical properties are mutually exclusive. Here, we utilize self-assembled polymeric carbon precursor materials in combination with scalable nano-imprinting lithography to produce nanoporous carbon nanopillars. Remarkably, nanoporosity induced via sacrificial template significantly reduces the mass density of amorphous carbon to 0.66 ~ 0.82 g cm−3 while the yield and fracture strengths of nanoporous carbon nanopillars are higher than those of most engineering materials with the similar mass density. Moreover, these nanopillars display both elastic and plastic behavior with large fracture strain. A reversible part of the sp2-to-sp3 transition produces large elastic strain and a high loss factor (up to 0.033) comparable to Ni-Ti shape memory alloys. The irreversible part of the sp2-to-sp3 transition enables plastic deformation, leading to a large fracture strain of up to 35%. These findings are substantiated using simulation studies. None of the existing structural materials exhibit a comparable combination of mass density, strength, deformability, and damping capability. Hence, the results of this study illustrate the potential of both dense and nanoporous amorphous carbon materials as superior structural nanomaterials. Simultaneous achievement of lightweight and high strength is challenging. Here, authors combine self-assembly of nanoscale block copolymer and carbonization to create nanoporous amorphous carbon materials, which have the density of elastomers or plastic but the strength of metals or alloys. [ABSTRACT FROM AUTHOR]

Polymer-derived silicon oxycarbide (SiOC) ceramics have garnered significant attention as novel silicon-based anode materials. However, the low conductivity of SiOC ceramics is a limiting factor, reducing both their rate capability and cycling stability. Therefore, controlling the free carbon content and its degree of graphitization within SiOC is crucial for determining battery performance. In this study, we regulated the free carbon content using divinylbenzene (DVB) and controlled the graphitization of free carbon with the transition metal iron (Fe). Through a simple pyrolysis process, we synthesized SiOC ceramic materials (CF) and investigated the impact of Fe-induced changes in the carbon phase and the amorphous SiOC phase on the comprehensive electrochemical performance. The results demonstrated that increasing the DVB content in the SiOC precursor enhanced the free carbon content, while the addition of Fe promoted the graphitization of free carbon and induced the formation of carbon nanotubes (CNTs). The electrochemical performance results showed that the CF electrode material exhibited a high reversible capacity of approximately 1154.05 mAh g−1 at a low current density of 100 mA g−1 and maintained good rate capability and cycling stability after 1000 cycles at a high current density of 2000 mA g−1. [ABSTRACT FROM AUTHOR]

In pursuit of highly active zinc–air battery (ZAB) catalysts, nitrogen doping has proven key to enhancing carbon-based non-metallic catalysts' performance in the oxygen reduction reaction (ORR). This study employed a novel method to synthesize variously sized ZnO materials coated with ZIF-8. Notably, smaller particle sizes correlated with reduced activation energy. ZnO-12, the smallest variant, fully carbonized at 800 °C, resulting in zinc ion evaporation and the formation of an amorphous carbon nano-hollow structure, ZIF8/ZnO-12. This material showcased remarkable ORR properties, with an onset potential of 0.9 V (vs. RHE) and a Tafel slope of 71.4 mV dec−1, surpassing the benchmark Pt/C catalyst and exhibiting excellent stability. Moreover, in ZAB tests, ZIF8/ZnO-12 achieved a specific capacity of 816 mA h g−1, outperforming Pt/C. DFT calculations indicate that under alkaline conditions, nitrogen-doped carbon materials containing adsorbed oxygen and doped oxygen exhibit lower catalytic activation energy for the ORR, which is beneficial for accelerating the ORR. This research provides valuable insights into designing more efficient carbon-based non-metallic catalysts for ZABs. [ABSTRACT FROM AUTHOR]

Low-cost amorphous nano-carbon (ANC) was employed as an absorbent to modify the microwave performance of AlN ceramics (AlN-4 wt% Y 2 O 3 - x wt% C, x = 0, 2.0, 3.8, 3.9, 4.0) via hot-pressing sintering, and the thermal and mechanical properties were also investigated. With the increase of ANC content from 0 to 4.0 wt%, the relative density of AlN composite decreases from 3.28 g cm−3 to 3.16 g cm−3 when sintered at 1800 °C for 2 h, and with the increase of sintering temperature from 1700 °C, the density of the 4.0 wt% ANC doped AlN composite presents trend of increase and reaches the maximum value of 3.16 g cm−3 at 1800 °C and then decreases. The XRD pattern shows that the composites are composed of AlN and Y–Al–O (YAG, YAP, YAM et al.) phases. SEM results indicate that average grain sizes for AlN and secondary phases gradually decrease with increasing carbon content, suggesting inhibited grain growth due to ANC addition. No obvious changes in phase constitution nor intensity changes were detected with the increase in carbon content and sintering temperature. As the carbon content increases from 0 to 4.0 wt%, the dielectric constant gradually increases from ∼9 to 13.89 at 10 GHz, the dielectric loss gradually increases from the vicinity of 10−3 to 0.38 at 10 GHz, and the reflective loss decreases from −27.92 dB to −49.40 dB, the thermal conductivity of the AlN-ANC composite decreases from 116.63 W m−1 K−1 to 50.13 W m−1 K−1. In addition, with 4.0 wt% ANC addition, the dielectric constant, dielectric loss, reflective loss, hardness, elastic modulus, bending strength, and fracture toughness are 13.89, 0.38, 49.40 dB, 6.4 ± 0.4 GPa, 262 GPa, 268.78 MPa, and 1.4 ± 0.1 MPa m1/2, respectively. Its ability to efficiently absorb microwave energy enhances the performance of devices including radar systems, communication equipment, and microwave heating systems, making it a promising candidate for microwave vacuum electronic applications. [ABSTRACT FROM AUTHOR]

The rational design of efficient and economical bifunctional electrocatalysts remained a challenge for overall water electrolysis. In this work, the Ni‐boride/ phosphide particles anchored amorphous B‐doped carbon layer with hierarchical porous characteristics in Ni foam (Ni3P/Ni3B/B−C/NF) was fabricated for overall water splitting. The Boroncarbide (B4C) power was filled and fixed in the NF interspace through the electroplating and electroless plating, and then annealed in vacuum high temperature. The amorphous B−C layer derived from the B4 C not only speeded up the electron transport, but also cooperate with Ni‐boride/phosphide to enhance the electrocatalytic activity for HER and OER synergistically. Furthermore, the hierarchical porous architecture of Ni3P/Ni3B/B−C/NF increased space utilization to load more active materials. The self‐supported Ni3P/Ni3B/B−C/NF electrode possessed a low overpotential of 212 and 280 mV to deliver 100 mA cm−2 for HER and OER, respectively, and high stability for 48 h. In particular, the electrolyzer constituted with the Ni3P/Ni3B/B−C/NF bifunctional electrocatalyst only required a voltage of 1.59 V at 50 mA cm−2 for water electrocatalysis under alkaline medium, and demonstrated long‐term stability for 48 h. This study provides a new technical path for the development of bifunctional of transition metal borides to promote the application of hydrogen production from water splitting. [ABSTRACT FROM AUTHOR]

As a novel cross‐structured 2D material, violet phosphorus (VP) promises to further develop the dynamic performance, energy efficiency, and service lifetime of mechanical components owing to its high strength and toughness, large carrier mobility, wide bandgap, and good friction‐reducing properties. In this work, the partially oxidized violet phosphorus nanosheets (oVP) are synthesized and employed as the lubricating additives in the poly alpha olefin (PAO) oil environment with less oleic acid (OA) improver, which can trigger the macroscale superlubricity on the diamond‐like carbon (DLC) film deposited steel surface at high loading pressures (>800 MPa) and sliding speeds (>0.1 m s−1). The friction coefficient (COF) of the steel‐DLC tribopair lubricated by the oVP‐PAO oil can reduce down to 0.0064 with little wear. At the high‐pressure sliding interface, the force‐thermal coupling action during the running‐in process promotes the cleavage and recombination of oVP nanosheets and OA molecules to form a reliable chemical adsorption tribofilm mainly composed of phosphorus oxides and amorphous carbon, which prevents the original asperities from direct contact and provides an ultralow shear strength. These findings suggest a new method to achieve macroscale oil‐based high‐pressure superlubricity for engineering steel through the lubrication and catalyzation effects of oVP. [ABSTRACT FROM AUTHOR]

Disordered carbon is the state of the art anode material for Na‐ion batteries due to their increased interlayer spacing and good electronic conductivity. However, its practical application is hindered by average specific capacity, poor rate performance, low coulombic efficiency and limited cycling stability. Herein, we report the superior pseudocapacitance enhanced Na‐ion storage of in situ surface functionalized carbon nanosheets. Anodes composed of ultrathin (~15 nm) carbon nanosheets demonstrated excellent reversible specific capacity (375 mAh/g at 25 mA/g), rate performance (150 mAh/g at 2 A/g), long‐term cycling performance (1000 cycles at 1 A/g) and coulombic efficiency (~100 %). Considerably higher pseudocapacitance (up to ~78 %) is also identified in this case compared to amorphous carbon particles. Spectroscopic and electrochemical studies proved Na‐ion intercalation in to the disordered carbon and pseudocapacitive storage driven by oxygen‐containing surface functional groups. Outstanding electrochemical performance is credited to the synergy between diffusion limited intercalation and pseudocapacitive surface Na‐ion storage. The demonstrated synthetic method of in situ functionalized carbon nanosheets is inexpensive and scalable. The strategy of functional group and morphology induced pseudocapacitive Na‐ion storage offer new prospects to design high‐performance Na‐ion battery electrodes. [ABSTRACT FROM AUTHOR]

This work compared C4F8 and C4H2F6 gases (as third components in CF4 + He gas mixture) for the high aspect ratio etching of SiO2 through the amorphous carbon layer (ACL) mask. The research scheme included the study of gas‐phase plasma characteristics, etching kinetics, and etching profiles. It was found that CF4 + C4F8 + He and CF4 + C4H2F6 + He gas mixtures are featured by quite close plasma parameters, the kinetics of electron‐impact processes, and ion bombardment intensities. At the same, the use of C4H2F6 provides a bit lower F atom density together with a bit higher polymerizing ability. All these factors cause lower absolute etching rates for both SiO2 and ACL but provide better SiO2/ACL/ACL selectivity and profile features. [ABSTRACT FROM AUTHOR]

To investigate the application of Ni3Al‐based superalloys in gas turbine cycle systems, this experiment exposed Ni3Al‐based superalloys to a 600°C/5 MPa environment with 99.995% pure CO2 gas. The corrosion and carburization behaviors and mechanisms were investigated in detail. The results reveal that with prolonged thermal exposure, the surface oxides of the samples tend to develop a continuous and homogeneous transition state alumina layer. This layer serves as a protective barrier, preventing the penetration and corrosion of external carbon‐containing and oxygen‐containing substances into the matrix. A small amount of carbon‐containing hazardous substances still penetrates the oxide layer or grain boundaries through highly diffusive pathways such as nanochannels, pores, and cracks, because the transition state of alumina is not completely dense. This leads to carbon deposition at the interface between the oxide layer and the matrix, where a mixture of alumina and amorphous carbon is formed at the interface. [ABSTRACT FROM AUTHOR]

Ceramics can be traditionally classified as structural and functional ones. However, the miniaturization and multi‐functionalization of various devices require ceramics to have both structural and functional properties. In this work, we aimed to develop structure‐function integrated ZrO2–SiO2 nanocrystalline glass–ceramics (NCGCs) by in situ formation of homogenously distributed amorphous carbon. By reducing the calcination temperature of carbon‐containing powder, organic carbon groups were partially retained in the powder and they transformed to amorphous carbon in the sintered NCGCs. At micrometer scale, the carbon was homogenously distributed in the NCGCs, avoiding the commonly encountered agglomeration problem of carbon fillers. The effects of carbon on the microstructure, mechanical properties, wear resistance, and dielectric properties of the NCGCs were investigated. Results showed that the in situ formed amorphous carbon was homogenously distributed in the ZrO2 nanocrystallites. Meanwhile, the amorphous carbon strongly bonded with the ZrO2–SiO2 NCGCs. Only a small amount of carbon was combusted even after annealing at 1000°C for 3 h. The formation of amorphous carbon led to an improvement of nanohardness and wear resistance of the NCGCs, while slightly reducing Young's modulus and flexural strength. The electromagnetic wave transmission performances were improved due to the formation of amorphous carbon. The current study paves a new way for developing structure‐function integrated glass–ceramics through in situ formation of carbon. The prepared structure‐function integrated ZrO2–SiO2 NCGCs have great potential to be used as radome and antenna windows of aerospace aircrafts that work in harsh environment. [ABSTRACT FROM AUTHOR]

[Display omitted] In this work, the nanocables of few-layered ReS 2 nanosheets sandwiched between carbon nanotubes (CNTs) and nitrogen-doped amorphous carbon (NC) coating (i.e., CNT@ReS 2 @NC) are synthesized as high-performance anodes of both potassium-ion batteries (PIBs) and sodium-ion batteries (SIBs). The CNT@ReS 2 @NC nanocables with dual carbon modifications have the several advantages for efficient K+/Na+ storage. The few-layered ReS 2 nanosheets with a wide interlayer spacing of 0.64 nm contribute to accelerated reaction kinetics for fast K+/Na+ intercalation/extraction. The carbon nanotube skeleton with a hollow interior can effectively relieve the volume change and serve as a robust conductive network to boost structural stability. The NC layer provides rich defects as active sites and suppresses the shuttle effect of polysulfides produced in discharge/charge processes. Consequently, the CNT@ReS 2 @NC nanocables possess outstanding electrochemical performance in both PIBs and SIBs owing to the synergistic effect from the different components. A long cycling lifespan of 3500 cycles with a maintained discharge capacity of 125 mAh/g is achieved for CNT@ReS 2 @NC at 1 A/g in PIBs. In SIBs, it can keep a high capacity of 202 mAh/g over 3000 cycles at 5 A/g. Moreover, the CNT@ReS 2 @NC||Na 3 V 2 (PO 4) 3 full cell can exhibit remarkable cycling performance, yielding a low capacity decay rate of 0.019 % per cycle over 1000 cycles at 2C. [ABSTRACT FROM AUTHOR]

In this study, we successfully obtained crystalline silicon from silica powder using a metal-induced crystallization method. For this purpose, powders were first prepared from organosilicon compounds and finely dispersed aluminum particles, then their metal-induced crystallization was carried out by annealing at the temperature of 570 °C. Powders of organosilicon compounds (tetraethoxysilane and polyethylhydrosiloxane) were prepared by different technological operations in order to determine precisely the presence of carbon in the product. The results showed that the presence of carbon in silica powder affects the production of crystalline silicon. In silica powders containing no carbon, the formation of crystalline substances does not occur at the annealing temperature of 570 °C. The results of this study are of great importance for the production of polycrystalline silicon powders obtained at reduced temperatures. [ABSTRACT FROM AUTHOR]

Amorphous carbon coatings are widely used due to their beneficial friction and wear characteristics. A detailed understanding of their behavior during running-in, apart from model tribosystems, has yet to be obtained. Multiple analytical methods were used to detect the physical and chemical changes in a ta-C coating and its thermally sprayed, metallic counterpart after a running-in procedure with pin-on-disk experiments. Both coatings exhibited changes in their surface and near-surface chemistry. The mechanisms in and on the metallic coating were identified to be a mixture of the third-body type, with the formation of gradients in the microstructure and chemistry and an additional carbon-rich tribofilm formation on top. The ta-C coating's changes in chemistry with sp2 enrichment and lubricant element inclusions proved to be too complex to allocate them to tribofilm or third-body formation. [ABSTRACT FROM AUTHOR]

The shielded pair resonator method is a useful tool in the measurement of accelerator components, such as the beam screens used in the Large Hadron Collider (LHC), the High-Luminosity (HL) LHC, or future accelerators. It can measure the resistive losses at several frequency points by separating the resistive losses on the sample from other sources of losses. We built a new resonator to be inserted into a superconducting dipole magnet (peak magnetic field of 9.5 T) and to measure the surface resistance of beam screens, such as LHC beam screens coated with amorphous carbon (a-C). The device can measure surface resistance at any temperature between 4.2 K and 300 K, in the frequency range of 400 MHz to 1600 MHz. We conducted the first surface resistance measurements of two a-C coated beam screens at 4.2 K and showed that the 200 nm to 400 nm titanium underlayer plus 50 nm a-C only has a limited effect on the surface resistance. This first result supports the choice of this coating as baseline for the HL-LHC triplets magnets upgrade. The resonator will have an important role in the characterization of next-generation beam screens, such as a beam screen with laser-engineered surface structure (LESS). Further measurements of the LHC beam screen in the presence of magnetic fields up to 9.5 T and throughout the full temperature range are going to be reported separately. [ABSTRACT FROM AUTHOR]

The layer-by-layer deposition of molten polymer filament in fused deposition modeling (FDM) has evolved as a disruptive technology for building complex parts. This technology has drawbacks such as the anisotropic property of the printed parts resulting in lower strength for parts printed in the vertical Z direction compared with the other two planes. In this manuscript, we attempt to address these challenges as well as the lack of standardization in sample preparation and mechanical testing of the printed parts. The paper focuses on process parameters and design optimization of the ZX build orientation. Type I tensile bars in ZX orientation were printed as per the ASTM D638 standard using two (2B) and four (4B) tensile bar designs. The proposed design reduces material loss and post-processing to extract the test coupons. Printing a type I tensile bar in the ZX orientation is more challenging than type IV and type V due to the increased length of the specimen and changes in additional heat buildup during layer-by-layer deposition. Three different polymer composite systems were studied: fast-crystallizing nanofiller-based high-temperature nylon (HTN), slow-crystallizing nanofiller-based polycyclohexylene diethylene terephthalate glycol-modified (PCTG), and amorphous carbon fiber-filled polyetherimide (PEI-CF). For all the polymer composite systems, the 2B showed the highest strength properties due to the shorter layer time aiding the diffusion in the interlayers. Further, rheological studies and SEM imaging were carried out to understand the influence of the two designs on fracture mechanics and interlayer bonding, providing valuable insights for the field of additive manufacturing and material science. [ABSTRACT FROM AUTHOR]

In this study, we present a novel approach to synthesizing amorphous carbon from agricultural waste, specifically pineapple peel, for electrochemical energy storage applications. The research emphasizes the critical role of calcination temperature and the subsequent interplay with different electrolytes (basic, neutral, and acidic) to tailor the material's properties for improved performance. A controlled calcination of the bio-waste was carried out at varying temperature of 400, 500, and 600 °C which yielded three separate samples. The sample calcinated at 500 °C is considered the best sample among the three, demonstrating the most favourable electrochemical properties. The calcination temperature was found to be pivotal in determining the material's structural and functional characteristics particularly for the said best sample, which exhibited an optimal balance of morphological structure and functional groups that facilitated enhanced charge storage and energy density, especially when interfaced with acidic electrolytes. Comprehensive characterization through XRD and FTIR affirmed the amorphous nature of the carbon and the presence of electrochemically active functional groups. Electrolyte selection proved to be a determining factor in the material's capacitive behaviour, with each electrolyte types bringing forth distinct capacitance and energy density profiles. The sample calcined at 500 °C consistently showed good performance in all the electrolyte system, and outperformed in acidic media due to the optimal interaction between the electrolyte ions and the tailored surface chemistry of the carbon. The insight from this research highlights the influence of calcination temperature in modifying the physical and chemical characteristics of carbon materials derived from biomass, without the need for additional porosity-enhancing treatments. The results contribute to a greener pathway for producing advanced materials for energy storage, reinforcing the potential of agricultural by-products in crafting next generation energy solution. [ABSTRACT FROM AUTHOR]