Electronic Channels Research Articles

Hydrogen-induced crack behavior of a precipitation-strengthened Ni50Cr20Co15Al10V5 high entropy alloy

The hydrogen-induced cracking behavior and mechanism of an L12-strengthened Ni50Cr20Co15Al10V5 high entropy alloy was evaluated using the tensile test after hydrogen charging. The microstructures and hydrogen-induced cracks were characterized by electron backscatter diffraction and electron channeling contrast imaging methods. The results revealed that hydrogen decreased the strain hardening rate and induced pronounced cracks, leading to significant degradation in elongation. After deformation, the local strain was concentrated in the precipitate-matrix interfaces. The precipitate-matrix boundary and the interior of precipitates were prone to hydrogen embrittlement, where hydrogen-induced cracks tended to propagate, attributing to the hydrogen-enhanced decohesion mechanism.

Embedding Pt in Ni-MOF/CdS organic-inorganic hybrid materials as electron channel to promote photogenerated carrier separation for enhanced photocatalytic hydrogen evolution under visible light

CdS exhibits a high photogenerated carrier yield, yet it is susceptible to photocorrosion due to the limited number of active sites. Ni-MOF boasts a considerable specific surface area and a plethora of active sites, yet it displays a low photogenerated carrier yield and suboptimal conductivity. In this study, the incorporation of Pt into a Ni-MOF/Pt/CdS hybrid material served as an electron transport channel, effectively addressing the limitations of CdS, Ni-MOF, and electrical conductivity. The results of electrochemical tests demonstrate that the electron transport and separation efficiency of the hybridised material is noteworthy. Following the performance test, the optimal visible photocatalytic hydrogen evolution rate of the Ni-MOF/Pt/CdS hybrid material was found to be 14.1 mmol h−1g−1, representing a significant enhancement of approximately 61.3 times compared to that of pure CdS. Furthermore, XPS analysis indicates the presence of Pt-S bonds, which effectively inhibit the oxidation of S2− to S on the CdS surface, thus alleviating the photocorrosion phenomenon and enhancing the cycling stability. This level of stability is maintained at 92.6 % after five cycles. This work offers a novel approach to addressing the limitations of inorganic catalysts, including the scarcity of active sites and the low photogenerated carrier yield, as well as the poor conductivity observed in organic catalysts.

Direct observation of the evolution behavior of micro to nanoscale precipitates in austenitic heat-resistant steel via electron channeling contrast imaging

Precipitation directly determines the high-temperature properties of the austenitic heat-resistant steels. The precipitations of MX, Z-phase, M23C6 and σ-phase, ranging from micrometers to nanometers, are commonly characterized using the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). However, details of their evolution behavior are still unclear due to the limited SEM resolution using the traditional sampling method and the limited spatial resolution of TEM. In this work, field emission SEM-based electron channel contrast imaging (ECCI) techniques with flexible sampling routes were introduced to observe the precipitation evolution behavior of HR3C steel after aging at 700 °C for 8095 h. We showed that the coarse primary-MX and Z-phase in the as-received steel are relatively stable during aging. The coarse M23C6 and tiny secondary Z-phase dispersions were rapidly formed along the grain/twin boundaries and within dislocation arrays inside the grain interior, respectively. We further found that the M23C6 at grain boundaries would change from continuous to semi-continuous due to the formation of σ-phases, while in twin boundaries, it would become continuous over aging. Moreover, we showed that the σ-phases were in-situ transformed from M23C6 at the grain boundaries via its dissolution, facilitating the nucleation of tiny Z-phase inside the σ-phase grains, and this phenomenon has not been reported so far. We have demonstrated that ECCI with an electrolytic-polishing-based sampling route is effective in revealing multi-scale precipitation with high-throughput efficiency, and it allows the direct observation of the complex behavior of precipitates down to the nanoscale using a bulk sample. This method can be used as an efficient way for the quantitative microstructure study.

Why Does a Transition Metal Dichalcogenide Nanoribbon Narrow into a Nanowire under Electron Irradiation?

Transition metal dichalcogenide (TMDC) nanowires have practical applications in 1D electron channels, spintronics, optoelectronics, and catalysis due to their authentic subnanometer width (<1 nm) and intrinsic metallicity. Although narrowing of a TMDC nanoribbon into a nanowire under electron irradiation has been frequently observed in the synthesis of TMDC nanowires, the mechanism underlying this unexpected structural transformation remains a mystery. Here, to reveal the underlying mechanism, we combine first-principles calculations with a global structure search of 1D nanowires and show that a nanoribbon of 1H-phase MoS2 with a width narrower than 6 rings is energetically unfavorable compared with its nanowire counterpart due to the edge-edge interaction. The bending effect induced by S defects under electron irradiation is the major driving force for the transition of MoS2 nanoribbon into a nanowire. We predict that the precursor of the Mo6S6 nanowire is a well-defined Mo11S11-i nanowire with an unexpected stoichiometry. The intrinsic local compressive strain triggers a phase transition from Mo11S11-i to its slightly modified sister nanowire, Mo11S11-ii, which is characterized by the configuration (Mo1S1)5&Mo6S6. Triggered by electron irradiation, the nanoribbon undergoes a step-by-step narrowing process with sequential peeling of a Mo1S1 fragment in each step to form a robust Mo6S6 nanowire. This unique narrowing mechanism is universal for the nanoribbon-to-nanowire transformation of other TMDCs under electron irradiation. Our study highlights a hitherto unexplored mechanism for creating individual M6X6 nanowires and contributes to an in-depth understanding of the narrowing of TMDC nanoribbons under electron irradiation.

Centralization of the System of E-Participation in the Russian Federation: Expert Interviews Data

This article presents the results of the study aimed at analyzing the institutional transformations of the E-Participation system in Russia. Since 2020, the e-participation system in Russia has undergone significant transformations associated with the introduction of centralized federal resources. As a result, different institutional models have been formed in different constituent regions of the Russian Federation, implying the refusal, autonomous preservation or coexistence of regional electronic channels with federal ones. The purpose of the study is to form an assessment of the changes taking place — the centralization of the e-participation system in the regions of the Russian Federation and the change in the degree of control over the activities of regional authorities by federal authorities. To achieve the goal of the study, expert interviews were conducted with 76 respondents, who are representatives of five key groups of subjects in the process of creating and using electronic channels for civic participation. The results of the study demonstrated an ambiguous opinion of experts on the ongoing changes and confirmed that the goals of federal authorities in the implementation of centralized projects of electronic citizen participation are aimed, among other things, at increasing the political controllability of regional authorities and collecting data for consideration when making management decisions.

Performance prediction applying different reduced turbulence models to the SMART tokamak

Abstract The SMall Aspect Ratio Tokamak (SMART) is currently being commissioned at the University of Seville and will be able to compare the performance of positive and negative triangularity plasmas at low aspect ratio. Predictive simulations have been performed for different machine scenarios and heating schemes using the TRANSP code. The objectives of these simulations are to predict the parameters expected in positive triangularity plasmas, to guide diagnostic development, and to validate transport models. Several reduced turbulence models have been used to predict electron and ion temperatures for the operational phase 2. All models provide similar results from approximately mid-radius to the separatrix but important discrepancies are found in the core region. These positive triangularity results are compared with experiments from a similar size machine like GLOBUS-M2. The multi-mode model (MMM) shows the best agreement. Simulations with different boundary conditions have been performed and no strong differences have been observed between them. The impact of neutral beam injection (NBI) on the predicted profiles has also been addressed. Rotation reduces turbulence levels so higher temperatures are achieved when included in the simulations. Studying the different contributions to the thermal diffusivities, it is observed that electron temperature gradient (ETG) turbulence dominates at the plasma core while micro-tearing modes (MTM) dominate at the edge in the electron channel. In the ion channel, the neoclassical contribution is dominant at the core and at the very edge while the Weiland component, which includes ion temperature gradient mode (ITG), trapped electron mode (TEM), kinetic ballooning mode (KBM), peeling mode (PM) and collisionless and collision dominated magnetohydrodynamic (MHD) modes governs the mid-radius region. For phase 3, two plasmas with different electron densities have been studied. The case with lower density matches well a specific discharge of GLOBUS-M2. The higher density plasma shows high performance with β N ≈ 3.8 .

Artificial Electron Channels Enable Contact Prelithiation of Li-Ion Battery Anodes with Ultrahigh Li-Source Utilization.

Contact prelithiation is widely used to compensate for the initial capacity loss of lithium-ion batteries (LIBs). However, the low utilization of the Li source, which suffers from the deteriorated contact interfaces, results in cycling degeneration. Herein, Li-Ag alloy-based artificial electron channels (AECs) are established in Li source/graphite anode contact interfaces to promote Li-source conversion. Due to the shielding effect of the Li-Ag alloy (50 at. % Li) on Li-ion diffusion, the dry-state interfacial corrosion is restricted. The unblocked electronic conduction across the AEC-involved interface not only facilitates the Li-source conversion but also accelerates the prelithiation kinetics during the wet-state process, resulting in an ultrahigh Li-source utilization (90.7 %). Implementing AEC-assisted prelithiation in a LiNi0.5Co0.2Mn0.3O2 pouch cell yields a 35.8 % increase in energy density and stable cycling over 600 cycles. This finding affords significant insights into the construction of an efficient prelithiation technology for the development of high-energy LIBs.

Artificial Electron Channels Enable Contact Prelithiation of Li‐Ion Battery Anodes with Ultrahigh Li‐Source Utilization

AbstractContact prelithiation is widely used to compensate for the initial capacity loss of lithium‐ion batteries (LIBs). However, the low utilization of the Li source, which suffers from the deteriorated contact interfaces, results in cycling degeneration. Herein, Li−Ag alloy‐based artificial electron channels (AECs) are established in Li source/graphite anode contact interfaces to promote Li‐source conversion. Due to the shielding effect of the Li−Ag alloy (50 at. % Li) on Li‐ion diffusion, the dry‐state interfacial corrosion is restricted. The unblocked electronic conduction across the AEC‐involved interface not only facilitates the Li‐source conversion but also accelerates the prelithiation kinetics during the wet‐state process, resulting in an ultrahigh Li‐source utilization (90.7 %). Implementing AEC‐assisted prelithiation in a LiNi0.5Co0.2Mn0.3O2 pouch cell yields a 35.8 % increase in energy density and stable cycling over 600 cycles. This finding affords significant insights into the construction of an efficient prelithiation technology for the development of high‐energy LIBs.

Simple power-efficient preamplifier-shaper channel for readout interface of silicon detectors

This paper presents the design and characteristics of a front-end readout system for silicon sensors used in nuclear spectroscopy studies. Furthermore, the study proposes circuit topologies that combine gain-boosting and class-AB techniques featuring a good performance regarding gain, accuracy, speed, linearity, and power consumption, meeting the stringent requirements of deep submicrometer CMOS technologies. The readout channel comprises a charge-sensitive amplifier with a tunable discharge time, pole-zero cancellation circuit, and first-order unipolar shaper with a peaking time of 90 ns. The building blocks are made up of single-stage op-amps, thus not requiring compensation. Furthermore, the circuit is optimized for a detector capacitance of 5 pF, and the noise performance is discussed. Experimental results in a 180 nm CMOS process and a supply voltage of ±0.9 V validate the designed front-end channel. The total area of the chip obtained was 0.028 mm2. The conversion gain was 3.1 mV/fC, and the system maintained linearity up to an input charge range of 150 fC with a maximum output swing of 460 mV and recovered to the baseline within 400 ns. The compact design and the power consumption of only 1.97 mW provided a feasible solution for current radiation detectors coupled to many highly dense electronic channels.

Cyclodextrin Metal-Organic Framework Functionalized Carbon Materials with Optimized Interface Electronics and Selective Supramolecular Channels for High-Performance Lithium-Sulfur Batteries.

During the reaction process in lithium-sulfur batteries, Lewis acidic lithium polysulfides (LiPSs) affect ion distribution and overall electrolyte stability, degrading battery performance and product distribution (e.g., Li2S). Here, a microenvironment regulation strategy with optimized interface electronics and selective supramolecular channels, is proposed to enhance LiPS reaction kinetics through Lewis basic γ-cyclodextrin metal-organic framework (γ-CDMOF). To validate this concept, γ-CDMOF is rapidly synthesized on 3D graphene foam (GF) via a microwave-assisted method, resulting in a γ-CDMOF/GF cathode for high-performance Li-S batteries. A range of analytical techniques combined with density functional theory (DFT) calculations confirm that introducing a Lewis basic supramolecular microenvironment mitigates the LiPSs shuttle effect, enhances polysulfide capture, and improves sulfur redox conversion. Additionally, COMSOL simulations reveal that the γ-CDMOF framework and oxygen sites significantly reduce volumetric expansion stress during the LiPS solid-liquid phase transition. Impressively, the γ-CDMOF/GF cathode exhibits exceptional performance, including a high specific capacity (1253.01 mAh g⁻¹ at 0.1C), excellent rate performance (589.68 mAh g⁻¹ at 5C), and long cycle life (over 1200 cycles). This study introduces a new concept of supramolecular microenvironment regulation and interfacial interaction strategy, offering a unique approach for the development of multifunctional electrode materials.

Nadh-dependent CO2 reductase on graphite for capacitive electrocatalytic interfacing mediated by solid-binding peptide.

NAD+/NADH-dependent CO2 reductase (CR) adapted from Candida boidinii (PDB ID: 5DNA) was introduced with a non-native graphite-specific peptide (Gr; IMVTESSDYSSY) as molecular binder to modify the native enzyme (CR-WT) with peptide insertion at N, C and NC terminus (CR-GrN, CR-GrC and CR-GrNC) to assess the influence of site-specific fusion on electrode binding. Graphite surface-binding activity relative to the electrode topography was evaluated for both native and synthetic CRs to establish the enzyme-electrode interfacing potentiality for efficient electron channelling. Impact of site-specific peptide fusion and amino-acids positioning was assessed for the active site availability/binding and adsorption/desorption ability towards efficient CO2-based redox catalysis. Solid-binding peptide and graphite surface interactive ability on direct electron transfer was studied with structural, enzymatic and electrochemical characterizations towards efficient CO2 electrosynthesis. Overall, enzymatic CO2 reduction to formate based on interactive ability of enzyme-electrode complex with peptide modifications and graphite surface towards possibility of bioelectronics upscaling was depicted.

Modulating the Cathode by Back-Gate for Planar Nanoscale Vacuum/Air Channel Electron Tube

Modulating the Cathode by Back-Gate for Planar Nanoscale Vacuum/Air Channel Electron Tube

Electronically Seamless Domain Wall of Chiral Charge Density Wave in 1T-TiSe2.

Domain walls (DWs) have been recognized to play crucial roles in various interesting properties and functionalities in quantum materials. A notable example is DWs in charge density wave (CDW), which are believed to provide metallic electron channels for emerging superconductivity. However, electronic states of DWs and the microscopic mechanism toward superconductivity have been elusive. Here, we clarify the atomic/electronic structure of DWs of the chiral CDW emerging in 1T-TiSe2, using scanning tunneling microscopy and density functional calculations. We reveal unambiguously the microscopic origin of chiral CDW as the C2 distortion in Se layers and its interlayer coupling. We further identify unique DWs connecting CDW domains of opposite chirality. The DWs are endowed with no in-gap state due to the characteristic multibands around the band gap, which defies the widely believed notion for CDW DWs. These results provide an important insight into the role of DWs in emerging superconductivity.

A hybrid MAPbI3/PEDOT-ZrO2 perovskedot composite for enhanced stability and charge transport in photo-batteries

Designing flexible photo-batteries that are capable of charged directly by light is critical for improving off-grid power options. This paper presents a unique photo-battery design that uses a MAPbI3/PEDOT as the effective light-harvesting and hole-transporting layer, and zirconium oxide (ZrO2) as the channel for electrons and hole-blocking layer. The MAPbI3 perovskite material absorbs sunlight and develops charge carriers, while PEDOT helps transport holes to the anode, improving charge separation and minimizing recombination losses. ZrO2, with its strong electron mobility and great chemical stability, provides fast transport of electrons to the cathode. It also efficiently blocks holes, increasing overall charge transfer dynamics. This improved design improves photo-conversion efficiency by up to 0.51 % and has a high capacity retention rate of around 96 % after 500 cycles. This improved MAPbI3/PEDOT/ZrO2 photo-battery could decrease light charging time by three times, enabling adaptable, light-rechargeable batteries more practical for real-world applications.

Defect Structure and Luminescence of κ‐Ga2O3 Micro‐Monocrystals

Wide bandgap orthorhombic polymorph of gallium oxide (κ‐Ga2O3) possessing a high spontaneous polarization grown on wurtzite‐type semiconducting substrates is considered to create a high mobility electron channel suitable for applications. Such κ‐Ga2O3 layers are composed of hexagon microprisms whose properties affect the lateral electric conductance. In this work, the structure and recombination properties of extended defects in individual “suspended” thin microprisms are investigated with transmission and scanning electron microscopy techniques (STEM, HR‐TEM) including cathodoluminescence (CL‐SEM). It is established that the microprism is composed of six equisized orthorhombic domains bounded by twin domain boundaries (TDBs) along the directions &lt;110&gt;. Twin domain contains a parallel array of antiphase boundaries (APB) of a high density stretched in the [010] direction. APBs possess steps or interruption and can form double oppositely shifted spatially separated layers (APB dipoles). TDBs on majority of their length are incoherent and serve as the border for the APB terminations. Panchromatic CL maps reveal either enhanced or reduced intensity of APB without noticeable spectral changes. CL intensity enhancement is proposed to be due to enhanced electron–hole generation caused by excess scattering of primary electron beam by APBs in thin films while, in fact, APB exhibits enhanced nonradiative recombination activity.

Conductance Channels in a Single-Entity Enzyme.

For a long time, the prevailing view in the scientific community was that proteins, being complex macromolecules composed of amino acid chains linked by peptide bonds, adopt folded structure with insulating or semiconducting properties, with high bandgaps. However, recent discoveries of unexpectedly high conductance levels, reaching values in the range of dozens of nanosiemens (nS) in proteins, have challenged this conventional understanding. In this study, we used scanning tunneling microscopy (STM) to explore the single-entity conductance properties of enzymatic channels, focusing on bilirubin oxidase (BOD) as a model metalloprotein. By immobilizing BOD on a conductive carbon surface, we discern its preferred orientation, facilitating the formation of electronic and ionic channels. These channels show efficient electron transport (ETp), with apparent conductance up to the 15 nS range. Notably, these conductance pathways are localized, minimizing electron transport barriers due to solvents and ions, underscoring BOD's redox versatility. Furthermore, electron transfer (ET) within the BOD occurs via preferential pathways. The alignment of the conductance channels with hydrophilicity maps, molecular vacancies, and regions accessible to electrolytes explains the observed conductance values. Additionally, BOD exhibits redox activity, with its active center playing a critical role in the ETp process. These findings significantly advance our understanding of the intricate mechanisms that govern ETp processes in proteins, offering new insights into the conductance of metalloproteins.

Enhanced visible light-driven photocathodic protection performance of CuBi2O4 modified TiO2 nanotube array S-type nano-heterojunction photoanodes for 316 stainless steel

CuBi2O4 (CBO) nanoparticle (NP)-sensitized TiO2 nanotube (NT) photoanodes have been prepared and optimized for high visible light utilization and photoconversion efficiency. The introduction of CBO significantly improved the charge generation/separation efficiency of the prepared photoanodes. The CBO-sensitized TiO2 NTs obtained with an electrodeposition time of 6 min had the best photocathodic protection (PCP) performance, and the photogeneration potential of CuBi2O4/TiO2 (CBOT) composites coupled to 316 stainless steel (SS) decreased by an additional 460 mV compared to that of TiO2. The CBO NPs were uniformly distributed on the TiO2 NTs to form tight interfacial bonds. Moreover, the one-dimensional TiO2 NTs act as direct electron channels, ensuring the fast collection of carriers generated by the system. The electronic lifetime of the 6CBOT composite is approximately 30 times that of the pure TiO2 material. In addition, the formation of S-type nano-heterojunction inside the CBOT not only promotes charge transfer in the system, but also retains a strong redox capacity compared to that of single TiO2 NTs. This work offers novel ideas in designing photoanode with efficient PCP property.

A Low‐Dimensional Donor‐Acceptor Perovskite for High‐Performance X‐Ray Detection

AbstractPerovskite materials hold significant promise for X‐ray detection due to their high X‐ray attenuation coefficient, efficient charge mobility, and tunable compositions and optoelectronic properties. Nonetheless, extracting the charges deep inside the thick semiconductors remains a challenge. Here, the 1D cytidine lead bromide perovskite (CytPbBr3) with a regularly arranged Donor (D)–Acceptor (A) heterojunction structure is reported. The organic interlayer contributes to the conduction band, while the inorganic framework constructs the valance band. Such a D–A heterojunction structure offers two separate channels for electrons and holes transport, suppressing the charge recombination rates with improved charge collection efficiency, and thus yields a high device sensitivity of 1.2 × 106 µC Gyair−1 cm−2 with a low noise equivalent dose (NED) of 44.6 pGyair.

Modulating dual carrier-transfer channels and band structure in carbon nitride to amplify ROS storm for enhanced cancer photodynamic therapy

Graphite carbon nitride (CN) eliminates cancer cells by converting H2O2 to highly toxic •OH under visible light. However, its in vivo applications are constrained by insufficient endogenous H2O2, accumulation of OH− and finite photocarriers. We designed Fe/NV-CN, co-modified CN with nitrogen vacancies (NV) and ferric ions (Fe3+). NV and Fe3+, not only adjust the band structure of CN through quantum confinement effect and the altered coupled oscillations of atomic orbitals to facilitates •OH production by oxidizing OH−, but also construct dual carrier-transfer channels for electrons and holes to respective active sites by introducing stepped electrostatic potential and shortening three-electron bonds, thereby involving more carriers in •OH production. Fe/NV-CN, the novel reactor, effectually produces vast •OH under illumination by expanding OH− as the raw material of •OH and augmenting carriers at active sites, which induces cancer cell apoptosis by disrupting mitochondrial function for significant shrinkage of Cal27 cell-induced tumor under illumination. This work provides not only an effective photosensitizer avoiding the accumulation of OH− for cancer therapy but also a novel strategy by constructing dual carrier-transfer channels on semiconductor photosensitizers for improving the therapeutic effect of photodynamic therapy.

Damage-tolerant oxides by imprint of an ultra-high dislocation density

Dislocations in ductile ceramics offer the potential for robust mechanical performance while unlocking versatile functional properties. Previous studies have been limited by small volumes with dislocations and/or low dislocation densities in ceramics. Here, we use Brinell ball scratching to create crack-free, large plastic zones, offering a simple and effective method for dislocation engineering at room temperature. Using MgO, we tailor high dislocation densities up to ∼1015 m−2. We characterise the plastic zones by chemical etching, electron channelling contrast imaging, and scanning transmission electron microscopy, and further demonstrate that crack initiation and propagation in the plastic zones with high-density dislocations can be completely suppressed. The residual stresses in the plastic zones were analysed using high-resolution electron backscatter diffraction. With the residual stress being subsequently relieved via thermal annealing while retaining the high-density dislocations, we observe the cracks are no longer completely suppressed, but the pure toughening effect of the dislocations remains evident.