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The solid solution design strategy bolsters the comprehensive mechanical properties of high/medium entropy alloys (H/MEAs), yet its utilisation within hexagonal close-packed (HCP) H/MEAs remains notably limited. Here, exploring the impact of reduced Cr content (x = 0.3, 0.1, and 0) from the HfZrTiCr0.5 prototype alloy, our study successfully obtained a novel HCP single phase MEA and investigated the relationship between microstructure and mechanical properties. Decreasing Cr content led to the diminishing presence of the Laves phase, culminating in a single HCP phase solid solution at x = 0.1. The Laves phase, arising from negative enthalpy between Cr and other elements and lower atomic radius of Cr, acted as crack initiation sites, resulting in brittle fracture (x = 0.5) alloy and limited plasticity strain of 3.5% (x = 0.3). Conversely, the HfZrTiCr0.1 alloy exhibited impressive combined yield strength (1360 MPa) and plasticity strain (14.5%), attributed to prominent solid solution strengthening and enhanced dislocation movement within the solid solution structure. These findings offer insights into manipulating Cr content to form HCP solid solution structures, potentially broadening solid solution alloy design strategies for superior mechanical properties in HCP H/MEAs. [ABSTRACT FROM AUTHOR]

Developing light yet strong aluminum (Al)-based alloys has been attracting unremitting efforts due to the soaring demand for energy-efficient structural materials. However, this endeavor is impeded by the limited solubility of other lighter components in Al. Here, we propose to surmount this challenge by converting multiple brittle phases into a ductile solid solution in Al-based complex concentrated alloys (CCA) by applying high pressure and temperature. We successfully develop a face-centered cubic single-phase Al-based CCA, Al55Mg35Li5Zn5, with a low density of 2.40 g/cm3 and a high specific yield strength of 344×103 N·m/kg (typically ~ 200×103 N·m/kg in conventional Al-based alloys). Our analysis reveals that formation of the single-phase CCA can be attributed to the decreased difference in atomic size and electronegativity between the solute elements and Al under high pressure, as well as the synergistic high entropy effect caused by high temperature and high pressure. The increase in strength originates mainly from high solid solution and nanoscale chemical fluctuations. Our findings could offer a viable route to explore lightweight single-phase CCAs in a vast composition-temperature-pressure space with enhanced mechanical properties. By overcoming the limited solubility of other lighter components in aluminum using high pressure and high temperature, a low-density, high specific strength, and single-phase aluminum-based complex concentrated alloy is developed. [ABSTRACT FROM AUTHOR]

The dipole moment (µ) is a critical parameter in Janus structures, influencing band alignments and carrier transmissions. However, evaluating µ in 2D Janus layers is challenging due to the vast number of structures and the inefficiency of Kelvin probe force microscopy. Using the recently developed 2D Janus transition‐metal dichalcogenides (TMDCs) as a prototype, a descriptor is proposed based on fundamental parameters (atomic number and atomic radii) to investigate the relationship between atomic structures and µ. By constructing 621 structural models, this descriptor is applicable from monolayers to three‐layers. By considering shielding effect of terminal atoms, the performance of the descriptor has been significantly enhanced, resulting in a description accuracy of 94.6% for all TMDC systems. Based on this descriptor, the Anderson's Rule (AR) model can be extended to Janus bilayers in simulating band alignments, resulting in a substantial improvement in accuracy from 20.0% to 90.8%. This development holds crucial importance in screening Janus self‐doping P‐N junctions. The work provides an efficient descriptor based on inherent atomic properties for rapid determining dipole moment and band alignment in 2D Janus TMDCs, accelerating the design of devices with built‐in electronic field structures. [ABSTRACT FROM AUTHOR]

Constructing Sb atomic clusters with obvious size effect in Sb/C composites has great potential for boosting electrochemical reactivity toward ultrahigh rate and long‐term sodium storage. However, how to balance the contradiction between ultra‐small size of Sb atomic clusters and high loading in a specific Sb/C composite is an unprecedented challenge. Here, a facile in situ vaporization‐reduction strategy is presented for preparing Sb atomic clusters@N, S co‐doped carbon networks (Sb ACs@NSC). Featuring the high content of Sb atomic clusters (45.30 wt%, ICP) with superior electrochemical activity, robust Sb─O─C bond and N, S co‐doped conductive carbon matrix, the Sb ACs@NSC electrode possessed ultrafast electrochemical kinetics and impressive long‐term cycling stability for providing unprecedented rate capability of 245.7 mAh g−1 at ultrahigh rate of 80 A g−1 and maintaining highlighted capacity of 306.7 mAh g−1 after 1000 cycles under 10 A g−1, outperforming all reported Sb‐based materials for SIBs. The DFT calculations further revealed that the Sb─O─C bond and N, S co‐doped carbon matrix are beneficial for stable adsorption capabilities and fast electrochemical kinetics of Na+. The designing compromised dense Sb atomic clusters and powerful interface bond will light on developing advanced atomic materials for energy storage and conversion. [ABSTRACT FROM AUTHOR]

Machine learning has been widely used to guide the search for new materials by learning the patterns underlying available data. However, the pure prediction-oriented search is often biased to interpolation due to the limited data in a large unexplored space. Here we present a sampling framework towards extrapolation, that integrates unsupervised clustering, interpretable analysis, and similarity evaluation to sample target candidates with improved properties from a vast search space. Using the design of superalloys with improved γ ′ -phase solvus temperature ( T γ ′ ) as a model case, we start with sparse data, and by a few experiments, we find nine new superalloys with chemistries distinct to those in the training data. Three of them show improved T γ ′ by about 50 °C, a large enhancement for superalloys. Moreover, we find two features characterizing mismatch in atomic size and mixing enthalpy linearly effect. This work demonstrates the capability of unsupervised learning to search for new materials when limited data is available. [ABSTRACT FROM AUTHOR]

Noble gases record in their radiogenic/non-radiogenic isotope ratios the traces of accretion history and degassing events from the early Earth, including giant impacts and the magma ocean stage, to large-scale recent volcanism. The diffusional behavior of noble gases in silicate magmas is one of the essential parameters needed to correctly model devolatilization from the magma ocean and subsequent volcanic eruptions. Here, we study the diffusivity of He, Ne, Ar, Kr, and Xe in molten pyrolite using ab initio molecular dynamics. We find that the diffusivity of the noble gases decreases with increasing atomic size. The diffusion of Ar is comparable to that of Mg. We compute the partial molar volumes and find that at high pressure, He is almost one order of magnitude more compressible than the heavier noble gases. The analysis of the speciation of the noble gases in the melt indicates that the lifetime of the coordination polyhedra formed with O is not sensitive to the mass of the noble gases. Finally, we compute the electron localization function along the Xe–O interatomic vectors and show that there is no chemical bonding between the Xe and surrounding O atoms from the hosting silicate melt. [ABSTRACT FROM AUTHOR]

Alloying elements segregating to grain boundaries (GBs) is vital in determining structural stability and mechanical properties of alloys, especially in high‐entropy alloys (HEAs) that consist of multiple elements. However, some details remain unclear, such as the process of varied atoms (Cr and Co) cosegregation to GBs in FeNiCrCo alloy. Therefore, the competition and cooperation between Fe, Ni, Cr, and Co atoms segregating to GBs of FeNiCrCo alloy were investigated via molecular dynamic (MD) simulation. Five [110] symmetric tilt GBs of FeNiCrCo were applied to study the relation between the tendency of atomic segregation especially Cr and Co and GB characters including GB energy and GB excess free volume (GB excess volume). A competitive segregation phenomenon between Cr and Co atoms was discovered, which could be dominated by GB excess volume and different atomic radii among components. [ABSTRACT FROM AUTHOR]

Deformation twinning creates a three-dimensional twin domain via the migration of forward, normal and lateral twin boundaries (TBs) with respect to twin shear direction, normal to twin plane and twin lateral direction. Solute segregation and pinning effect on the forward and normal TBs have been experimentally observed and demonstrated via atomistic simulations. Here, we conducted a comprehensive study of solute segregation and the pinning effect on the lateral TBs in Mg. First-principles density functional theory calculations were used to obtain the segregation and formation energies of 19 alloying elements in coherent regions of lateral TBs. Alloying elements with greater difference in atomic radius from Mg generally show more negative segregation energy. Moreover, alloying elements with good solubility are selected to demonstrate the pinning effect on a coherent interface. Ge, Ga, Y, Gd, La and Ca show negative segregation energy and solubility energy, indicating that these elements can form stable segregation and have a strong pinning effect at the lateral boundary. Molecular dynamics simulations revealed that solutes in coherent regions are more effective in pinning lateral TBs than those in misfit regions. The results provide insight into the selection of solute atoms for tailoring twinning behavior. [ABSTRACT FROM AUTHOR]

Using ab initio molecular dynamics (AIMD), the cascade collision process in GaN irradiated by low‐energy electron beam and the temperature effect on the threshold displacement energy (TDE) are investigated. The temperature effect of the TDE is found to exhibit different patterns for Ga and N primary knock‐on atoms (PKAs). In the considered energy range of initial kinetic energy (40 to 80 eV), displacements induced by Ga PKA show high uncertainty, i.e., the TDE energy strongly depends on the initial configurations, and kinetic energies higher than TDE does not ensure the displacements that form defects. On the contrary, temperature shows relatively small effect on its TDE and displacement induced by N PKAs, which can essentially occur when the PKA kinetic energy is higher than the TDE. Such different effects are possibly due to the different atomic radii of the two elements and the different energy barriers to overcome. Ga PKAs, which have larger atomic radii, are relatively difficult to stabilize in the crystal and tend to relax to its original position with the assistance of thermal vibrations, and vice versa for N PKAs. The simulation results provide a new understanding of TDE and the cascade collisions of PKAs in GaN at finite temperatures, which can be instructive for improving the radiation resistance of GaN devices. [ABSTRACT FROM AUTHOR]

The high degree of corrosivity and reactivity of bromine, which is released from various sources, poses a serious threat to the environment. Moreover, its coexistence with iodine forming an equilibrium compound, iodine monobromide (IBr) necessitates the selective capture of bromine from halogen mixtures. The electrophilicity of halogens to π‐electron rich structures enabled us to strategically design a covalent organic framework for halogen capture, featuring a defined pore environment with localized sorption sites. The higher capture capacity of bromine (4.6 g g−1) over iodine by ~41 % shows its potential in selective capture. Spectroscopic results uncovering the preferential interaction sites are supported by theoretical investigations. The alkyne bridge is a core functionality promoting the selectivity in capture by synergistic physisorption, rationalized by the higher orbital overlap of bromine due to its smaller atomic size as well as reversible chemical interactions. The slip stacking in the structure has further promoted this phenomenon by creating clusters of molecular interaction sites with bromine intercalated between the layers. The inclusion of unsaturated moieties, i.e. triple bonds and the complementary pore geometry offer a promising design strategy for the construction of porous materials for halogen capture. [ABSTRACT FROM AUTHOR]

In this study, we have conducted a thorough investigation into the influence of the atomic radius of transition metals on the structural, electronic, and optical properties of nanolaminated borides MAlB (M = Cr , Mo, W) using first principles calculation. The validity and dependability of our calculation parameters are confirmed and compared with other available data sets. The calculated elastic constants reveal stronger resistance to deformation along the c direction as compared to the a- and b-directions. The mechanical properties of these borides increased in tandem with the atomic radius of transition metal. The chemical bonding within the borides is a mix of metallic and covalent bonds. Interestingly, there is a decrease in the boride metallicity concurrent with an increase in the atomic radius of the transition metal. Optical property analysis shows promise for these borides as absorbent materials. Furthermore, there is a correlation between the increase in the atomic nucleus of the transition metal and the increase in the maximum absorption coefficient. [ABSTRACT FROM AUTHOR]

In this study, we fabricated deep ultraviolet (DUV) photodetectors based on perovskite thin films doped with halide materials using formamidinium bromide (FABr) and methylammonium iodide (MAI). The device was fabricated using a simple surface engineering technique by post-treating the MAPbI3 perovskite film with an FABr solution. This film acts as a light absorption layer, like a depletion layer with a p-i-n (PIN) structure, with n-type of SnO2-SDBS and p-type of spiro-OMeTAD. Adding 0.10 M MACl to the MAPbI3 precursor solution during the manufacturing process could effectively reduce the trap density compared with existing films. Films with MACl added in the two-step process can control a wide band gap and improve crystallinity. In addition, the Cl atom has a smaller atomic radius than iodine and a higher electronegativity of 3.16, which can improve phase stability, and the effect of the added Cl− increases the electron mobility of the perovskite, showing a fast response. [ABSTRACT FROM AUTHOR]

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Materials are needed to preferentially remove heavy metal pollutants from waste streams. Here, atomic scale simulation, based on density functional theory, is used to predict encapsulation energies and electronic structures of the one-dimensional yttrium silicide electride (Y5Si3:e–) hosting the heavy metals such as zinc (Zn), cadmium (Cd), mercury (Hg), chromium (Cr), nickel (Ni), copper (Cu), or lead (Pb). Assuming that the metals are present as dimers in gaseous waste, encapsulation is highly exoergic for those metals with incomplete p or d electrons (Cr, Ni, Cu, and Pb). Of the heavy metals with complete d shells (Zn, Cd, and Hg), only Zn exhibits strong encapsulation. Differences in encapsulation behavior are analyzed in terms of electronic structures, electron affinities, atomic radii, and Bader charges. [ABSTRACT FROM AUTHOR]

Materials are needed to preferentially remove heavy metal pollutants from waste streams. Here, atomic scale simulation, based on density functional theory, is used to predict encapsulation energies and electronic structures of the one-dimensional yttrium silicide electride (Y5Si3:e–) hosting the heavy metals such as zinc (Zn), cadmium (Cd), mercury (Hg), chromium (Cr), nickel (Ni), copper (Cu), or lead (Pb). Assuming that the metals are present as dimers in gaseous waste, encapsulation is highly exoergic for those metals with incomplete p or d electrons (Cr, Ni, Cu, and Pb). Of the heavy metals with complete d shells (Zn, Cd, and Hg), only Zn exhibits strong encapsulation. Differences in encapsulation behavior are analyzed in terms of electronic structures, electron affinities, atomic radii, and Bader charges. [ABSTRACT FROM AUTHOR]

The influence of Al on the defect behaviors of AlxCoCrFeNi high-entropy alloys (HEAs) is studied by ab initio calculations. The lattice distortion, defect formation energies, and defect migration energies were calculated for different Al concentrations ranging from 0 to 6.25 at. %. First, the increase in the lattice distortion of AlxCoCrFeNi by the addition of Al is demonstrated, but the increment is smaller than that predicted by the atomic size difference of constituent elements. Second, although formation energies of Al vacancies and dumbbells containing Al are higher, the addition of Al decreases the average formation energies of vacancies and interstitials, which is probably due to the Al-induced local strain field and lattice distortion. The migration energies of interstitials and vacancies exhibit opposite variations, the migration energies of interstitials are increased while that of vacancies are decreased with the Al content. Moreover, the distributions of formation and migration energies of both defects are significantly broadening with increasing Al content, which could further enhance the characteristic effects of HEAs and play a more important role in the irradiation resistances of HEAs. Based on the calculation results, the effects of Al on the irradiation responses of AlxCoCrFeNi are discussed. [ABSTRACT FROM AUTHOR]

VV10 is a powerful nonlocal density functional for long-range correlation that is used to include dispersion effects in many modern density functionals, such as the meta-generalized gradient approximation (mGGA), B97M-V, the hybrid GGA, ωB97X-V, and the hybrid mGGA, ωB97M-V. While energies and analytical gradients for VV10 are already widely available, this study reports the first derivation and efficient implementation of the analytical second derivatives of the VV10 energy. The additional compute cost of the VV10 contributions to analytical frequencies is shown to be small in all but the smallest basis sets for recommended grid sizes. This study also reports the assessment of VV10-containing functionals for predicting harmonic frequencies using the analytical second derivative code. The contribution of VV10 to simulating harmonic frequencies is shown to be small for small molecules but important for systems where weak interactions are important, such as water clusters. In the latter cases, B97M-V, ωB97M-V, and ωB97X-V perform very well. The convergence of frequencies with respect to the grid size and atomic orbital basis set size is studied, and recommendations are reported. Finally, scaling factors to allow comparison of scaled harmonic frequencies with experimental fundamental frequencies and to predict zero-point vibrational energy are presented for some recently developed functionals (including r2SCAN, B97M-V, ωB97X-V, M06-SX, and ωB97M-V). [ABSTRACT FROM AUTHOR]

As devices scale closer to the atomic size, a complete understanding of the physical mechanisms involving defects in high-κ dielectrics is essential to improve the performance of electron devices and to mitigate key reliability phenomena, such as Random Telegraph Noise (RTN). In fact, crucial aspects of defects in HfO2 are still under investigation (e.g., the presence of metastable states and their properties), but it is well known that oxygen vacancies (V+s) and oxygen ions (O0s) are the most abundant defects in HfO2. In this work, we use simulations to gain insights into the RTN that emerges when a constant voltage is applied across a TiN/(4 nm)HfO2/TiN stack. Signals exhibit different RTN properties over bias and, thus, appear to originate from different traps. Yet, we demonstrate that they can be instead promoted by the same O0s which change their capture (τc) and emission (τe) time constants with the applied bias, which, in turn, changes the extent of their electrostatic interactions with the traps that assist charge transport (V+s). For a certain bias, RTN is given by the modulation of the trap-assisted current at V+s induced by trapping/detrapping events at O0s, which are, in turn, influenced by the bias itself and by trapped charge at nearby O0s. In this work, we demonstrate that accounting for the effect of trapped charge is essential to provide accurate estimation of the RTN parameters, which allow us to retrieve information about traps and to explain key mechanisms behind complex RTN signals. [ABSTRACT FROM AUTHOR]

In the present work, we study the behavior of the noble gases He, Ne, Ar, and Kr inside a hydroquinone clathrate (HQC) by using all-atom molecular dynamics. Larger elements of the same group were not considered due to their inability to fit inside the HQC cavities. By using the umbrella sampling technique, we have obtained the following inter-cage transition barriers—which are arguably the main factor determining the type of diffusion of the gases—at 310 K and 0.1 MPa: 1192; 2204; 6450; 10 730 kJ mol−1 for the guests He, Ne, Ar, and Kr, respectively. These energy barriers were found to have a linear relation with atomic radii (σ). We have tested this tendency with CH4, due to its intermediate size between Ar and Kr, obtaining a barrier of 8926 kJ mol−1, in excellent agreement with the results for noble gases. [ABSTRACT FROM AUTHOR]

Heteroatom doping, especially with elements of lower electronegativity and smaller atomic radius, can effectively modulate the electronic structure and surface properties of electron materials, facilitating the electrochemical performance of supercapacitors. Herein, we have designed boron-doped NiCoP nanoarrays grown on carbon cloth (B-NCP-CC) for supercapacitor cathode materials using a simple process method combining hydrothermal, calcined phosphating and boronation processes. The introduction of boron, with lower electronegativity (2.04) and smaller atomic radius (0.85 Å) than phosphorus (2.19 and 1.00 Å), induces electron redistribution and shortens the Ni/Co–B bonds, enhancing their redox activity and charge transfer kinetics. The boron doping greatly enables the B-NiCoP-CC-18 (NiCoP-CC borated for 18 h) cathode material to provide a high capacity of 801 C g−1. The assembled B-NiCoP-CC-18‖‖AC hybrid supercapacitor achieves a high energy density of 73.22 W h kg−1 at a power density of 963.8 W kg−1 and retains 90% capacity after 5000 cycles, significantly improving the stability of nickel-based materials. Besides, density functional theory (DFT) calculations further elucidate that the introduction of boron increases the d-band centers of Ni and Co in NiCoP, promoting the conductivity and enhancing the electrochemical properties. [ABSTRACT FROM AUTHOR]

Complex multi-element alloys are gaining prominence for structural applications, supplementing steels, and superalloys. Understanding the impact of each element on alloy surfaces due to oxidation is vital in maintaining material integrity. This study investigates oxidation mechanisms in these alloys using a model five-element equiatomic CoCrFeNiMn alloy, in a controlled oxygen environment. The oxidation-induced surface changes correlate with each element's interactive tendencies with the environment, guided by thermodynamics. Initial oxidation stages follow atomic size and redox potential, with the latter becoming dominant over time, causing composition inversion. The study employs in-situ atom probe tomography, transmission electron microscopy, and X-ray absorption near-edge structure techniques to elucidate the oxidation process and surface oxide structure evolution. Our findings deconvolute the mechanism for compositional and structural changes in the oxide film and will pave the way for a predictive design of complex alloys with improved resistance to oxidation under extreme conditions. Understanding the intricate relationship between alloying elements and oxidation processes is essential for the integrity and performance of materials. Here, the authors study the effects of atomic size and redox potential to understand the oxidation process and structural changes in surface oxides. [ABSTRACT FROM AUTHOR]

Aluminum garnets display exceptional adaptability in incorporating mismatching elements, thereby facilitating the synthesis of novel materials with tailored properties. This study explored Ce3+-doped Tb3Al5−xScxO12 crystals (where x ranges from 0.5 to 3.0), revealing a novel approach to control luminescence and photoconversion through atomic size mismatch engineering. Raman spectroscopy confirmed the coexistence of garnet and perovskite phases, with Sc substitution significantly influencing the garnet lattice and induced A1g mode softening up to Sc concentration x = 2.0. The Sc atoms controlled sub-eutectic inclusion formation, creating efficient light scattering centers and unveiling a compositional threshold for octahedral site saturation. This modulation enabled the control of energy transfer dynamics between Ce3+ and Tb3+ ions, enhancing luminescence and mitigating quenching. The Sc admixing process regulated luminous efficacy (LE), color rendering index (CRI), and correlated color temperature (CCT), with adjustments in CRI from 68 to 84 and CCT from 3545 K to 12,958 K. The Ce3+-doped Tb3Al5−xScxO12 crystal (where x = 2.0) achieved the highest LE of 114.6 lm/W and emitted light at a CCT of 4942 K, similar to daylight white. This approach enables the design and development of functional materials with tailored optical properties applicable to lighting technology, persistent phosphors, scintillators, and storage phosphors. [ABSTRACT FROM AUTHOR]

In order to facilitate the prediction of some physical properties, we propose several simple formulas based on two parameters only, the metallic valence and metallic atomic radii. Knowing the composition, for single-phase alloys, the average parameters can be calculated by the rule of mixture. The input parameters can be obtained from tabulated databases. Adopting from the literature the results of Coulomb crystal model for metals and single-phase high-entropy alloys, we have derived formulas for the shear modulus (G) and the cohesion energy (Ecoh). Based on these parameters separately, we set up two formulas to estimate the hardness in the case of pure metals. For single-phase (solid-solution) HEAs, by simplifying the Maresca and Curtin model, we obtained a formula for estimating the hardness, which takes into account the atomic misfit in addition to G. The maximal hardness for single-phase HEA is approximately 600 kg/mm2 and is obtained for a composition with a valence electron concentration of approximately 6 ÷ 7. [ABSTRACT FROM AUTHOR]

In this work, we employ a phase field dislocation dynamics technique to simulate dislocation motion in body centered cubic refractory metals with diffusing interstitials. Two distinct systems are treated, Nb with O interstitials and W with H interstitials, to consider both relatively small and large atomic size interstitials. Simulations without and with driving stress are designed to investigate the role of interstitial type and mobility on the glide of edge- and screw-character dislocations. The simulations reveal the various short- and long-range dislocation-interstitial interactions that can take place and their dependency on interstitial type, site occupation, stress state, and mobility of the interstitials relative to dislocations. We show that while interstitial O increases the breakaway stress for both screw and edge dislocations in Nb, interstitial H in low H concentrations makes screw dislocations easier and the edge dislocations harder to move. The simulations find that screw dislocation glide is enhanced by the presence of interstitials in both systems. Edge dislocation glide is enhanced in W–H and inhibited in Nb–O. [ABSTRACT FROM AUTHOR]

This study conducts a comprehensive investigation into the electronic characteristics and optical behaviour of hetero-ring doped graphene quantum dots (GQDs) using a combination of density functional theory and many-body perturbation methods. The focus is on exploring a novel doping mechanism involving the interplay between the type and positioning of dopant rings, specifically Morpholone, Oxazole, and Thiazole rings. The doping process significantly alters the structural, electronic, and optical properties of the pristine GQD. Structural distortions are observed in the doped nanostructures due to variations in atomic radii and electronegativity among C, O, N, and S atoms. The HOMO-LUMO (H–L) band gap and optical gap exhibit reduction upon doping. Additionally, the absorption spectra of the doped nanostructures shift to lower energy levels compared to the pristine GQD. This finding, coupled with high binding energies and reduced singlet-triplet splitting, provide insights into the photophysical processes within each studied structure, suggesting potential applications. [ABSTRACT FROM AUTHOR]

Sensitivity enhanced dynamic nuclear polarization solid‐state NMR is emerging as a powerful technique for probing the structural properties of conformationally homogenous and heterogenous biomolecular species irrespective of size at atomic resolution within their native environments. Herein we detail advancements that have made acquiring such data, specifically within the confines of intact bacterial and eukaryotic cell a reality and further discuss the type of structural information that can presently be garnered by the technique's exploitation. Subsequently, we discuss bottlenecks that have thus far curbed cellular DNP‐ssNMR's broader adoption namely due a lack of sensitivity and spectral resolution. We also explore possible solutions ranging from utilization of new pulse sequences, design of better performing polarizing agents, and application of additional biochemical/ cell biological methodologies. [ABSTRACT FROM AUTHOR]

High-entropy alloys offer a simpler alternative to the precise balance of binary alloy designs in terms of chemical composition. Such alloys consist of at least five basic metallic elements with solute elements that have relatively similar atomic sizes, resulting in a roughly equimolar ratio. Alloys produced using this method exhibit extraordinary physical properties, attracting the attention of researchers. However, for them to be viable for industrial production, their economic value must also be reasonable. In this study, high-purity and commercial alloying elements were used to produce samples by arc melting. Structural analysis was conducted on the resulting samples, and the differences in their structural characteristics were examined through heat treatment. The high-purity high-entropy alloy samples showed a structure similar to that of the commercially pure sample before heat treatment. However, after heat treatment, it was found that different structures had formed in the commercial sample, likely due to the presence of small amounts of impurities in the content of the commercially pure alloy. [ABSTRACT FROM AUTHOR]

Strain- and defect-engineering are two powerful approaches to tailor the opto-electronic properties of two-dimensional (2D) materials, but the relationship between applied mechanical strain and behavior of defects in these systems remains elusive. Using first-principles calculations, we study the response to external strain of h-BN, graphene, MoSe2, and phosphorene, four archetypal 2D materials, which contain substitutional impurities. We find that the formation energy of the defect structures can either increase or decrease with bi-axial strain, tensile or compressive, depending on the atomic radius of the impurity atom, which can be larger or smaller than that of the host atom. Analysis of the strain maps indicates that this behavior is associated with the compressive or tensile local strains produced by the impurities that interfere with the external strain. We further show that the change in the defect formation energy is related to the change in elastic moduli of the 2D materials upon introduction of impurity, which can correspondingly increase or decrease. The discovered trends are consistent across all studied 2D materials and are likely to be general. Our findings open up opportunities for combined strain- and defect-engineering to tailor the opto-electronic properties of 2D materials, and specifically, the location and properties of single-photon emitters. [ABSTRACT FROM AUTHOR]

Hyperfine splitting frequency shifts of paramagnetic atoms (H, Li, Na, K, Rb, and Cs) induced by noble-gas collisions are calculated by perturbation theory. The finite sizes of the core orbitals of noble-gas atoms (He, Ne, Ar, Kr, and Xe) are taken into account by the modified pseudopotential. The wave function of the valence electron is orthogonalized to the core orbitals, leading to a correct calculation of the resonance frequency. Fitting results are compared for the wave function bases and the core orbital sizes. The best fits are obtained when the Hartree–Fock–Roothaan wave function is used for the ground state of paramagnetic atoms and when repulsion forces due to the outermost occupied orbitals of noble-gas atoms are considered. For all combinations of alkali-metal and noble-gas atoms, the obtained fitting parameters are close to the pseudopotential height of approximately 2.6 times the atomic radius. [ABSTRACT FROM AUTHOR]

• The presence of multiple elements, each with distinct mixing affinities, promotes an accelerated amorphization. The energetic state and atomic size disparities among these elements render the amorphous phase resistant to crystalline reversion upon annealing. • The formation energies reveal that the amorphous structure assumes the most stable configuration and is energetically favorable relative to crystalline phases like BCC, FCC, and HCP, thereby driving the transformations. • High-energy mechanical milling induces distortion, antisite defects, and the formation of nanograin boundaries in the intermetallic phase, disrupting the order in atomic configuration and promoting amorphization. We describe a novel mechanism for the synthesis of a stable high-entropy alloy powder from an otherwise immiscible Mg-Ti rich metallic mixture by employing high-energy mechanical milling. The presented methodology expedites the synthesis of amorphous alloy powder by strategically injecting entropic disorder through the inclusion of multi-principal elements in the alloy composition. Predictions from first principles and materials theory corroborate the results from microscopic characterizations that reveal a transition of the amorphous phase from a precursor intermetallic structure. This transformation, characterized by the emergence of antisite disorder, lattice expansion, and the presence of nanograin boundaries, signifies a departure from the precursor intermetallic structure. Additionally, this phase transformation is accelerated by the presence of multiple principal elements that induce severe lattice distortion and a higher configurational entropy. The atomic size mismatch of the dissimilar elements present in the alloy produces a stable amorphous phase that resists reverting to an ordered lattice even on annealing. [Display omitted] [ABSTRACT FROM AUTHOR]

Rare-earth AB 5 -type alloys have great application potential in solid-state hydrogen storage. To further improve their plateau characteristics and cycling life, the effects of Fe on the long-term hydrogen storage properties of LaNi 5- x Fe x (x = 0, 0.5, 1) alloys are studied, and the function mechanisms are revealed. Fe induces a (Fe,Ni) phase layer with good ductility around LaNi 5 main phase, which plays a buffer role to relieve the microstrain during hydrogen absorption/desorption, thus stabilizing the crystal structure and improving the cycling performance. Further, Fe with larger atomic radius than Ni relieves the compression from 12 o to 6 m site of the LaNi 5 phase, and suppresses the plateau splitting phenomenon, resulting in a single and long hydrogen absorption/desorption plateau throughout 1000 cycles. This study promotes the understanding and application of cheap and effective Fe in improving the hydrogen storage properties of AB 5 -type alloys during long-term cycling. [Display omitted] • Long-term H 2 storage properties of LaNi 5- x Fe x alloys during 1000 cycles are studied. • (Fe,Ni) phase layer is induced by Fe addition. • (Fe,Ni) phase with good ductility decreases microstrain of H 2 absorption/desorption. • Fe addition relieves the stress of 6 m to 12 o sites, and suppresses plateau splitting. • Appropriate amount of Fe stabilizes crystal structure and increases capacity retention. [ABSTRACT FROM AUTHOR]

Understanding the Hydrogen embrittlement (HE) mechanism on the miscroscopic level has been a long-standing challenge. In this work, a systematic computational work based on the first-principles simulations and Ref as well as the ab initio molecular dynamics unveiled the effects of 19 metallic solutes on the HE of AlMgZnCu alloys with Σ3(111), Σ5(210), Σ5(310), Σ7(123), and Σ9(221) grain boundaries (GBs). The effects of the atomic size of these solutes on the complex segregation energy (SE) and GB energy were investigated, and the effect of temperature on the H concentration of the AlMgZnCu alloys was analyzed using a Gaussian distribution of complex SE. It is determined that the HE process involves the following sequence of phenomena: fracture surface formation → crack propagation → GB fracturing. The key findings of this work are summarized as follows: (i) the SE and GB/free surface energy depends linearly on the atomic sizes of the alloy; (ii) the crack could be healed at a critical temperature of 673 K; (iii) A gene diagram has been developed to show the temperature dependence of the segregation and cohesion of H concentration. [Display omitted] • The crack could be cured at a critical temperature of 673 K. • A gene diagram has been developed to show the temperature dependence of the segregation and cohesion of H. • The SE and GB/free surface energy depends linearly on the atomic sizes of the alloy. [ABSTRACT FROM AUTHOR]

This study investigates the fracture toughness and toughening mechanism of (La0.2Nd0.2Sm0.2Eu0.2Y0.2)NbO4, a high entropy material characterized by a high thermal expansion coefficient and low thermal conductivity. Our finding demonstrates a noteworthy 50% increase in fracture toughness for (La0.2Nd0.2Sm0.2Eu0.2Y0.2)NbO4 (~3.09 MPa m0.5) compared to YNbO4 (~2.11 MPa m0.5). The superior fracture toughness for (La0.2Nd0.2Sm0.2Eu0.2Y0.2)NbO4 can be attributed to the two key factors: relatively easy ferroelastic domain switching and the presence of ultrahigh-density dislocations (~7 x 108 mm-2). The enhanced ferroelastic toughening in (La0.2Nd0.2Sm0.2Eu0.2Y0.2)NbO4 is associated with its distinct characteristics, large atomic radius (RA), significant tetragonality (c/a ratio), and lowmonoclinic β angle. These factors contribute to larger spontaneous strain, larger coercive strain, and lower transformation strain, respectively. These properties facilitate the formation and switching of the ferroelastic domains. In addition, the interactions between the large strain field surrounding the dislocations and the cracks facilitate crack deflection and bridging. The combined effect of ferroelastic toughening and ultrahigh-density dislocations ultimately leads to the significant improvement in the fracture toughness of (La0.2Nd0.2Sm0.2Eu0.2Y0.2)NbO4. [ABSTRACT FROM AUTHOR]

Slater's method is an integral part of the undergraduate experience. In actuality, Slater's method is part of an atomic model and not simply a set of rules. Slater's rules are a simple means for computing the effective nuclear charge experienced by an orbital. These rules are based on the shell-like structure of the Slater atom in which outer shell electrons are incapable of shielding inner electrons. Slater's model provides a qualitative description of the valence electrons in multi-electron atoms with tremendous ease. The model is useful for explaining atomic properties such as ionisation energy, electron affinity and atomic radius qualitatively. Slater's rules also correctly reproduce the Madelung rule of filling and the ionisation sequence (4s before 3d); however, these rules are not able to reproduce the anomalous configurations of atoms such as Cr and Cu. It is found that the atomic properties that Slater's model reproduces are all related to the exponential decay factor of the Slater orbital. We find—from estimating the polarity of a diatomic molecule using a simple model—that molecular polarity is related to the difference in the exponential decay factors of the valence orbitals of the two atoms, implying that the decay factor acts as the electronegativity of the atom. [ABSTRACT FROM AUTHOR]

In recent years, a novel two-dimensional semiconductor ZrX2 (X = Cl, Br, and I) has been found to have excellent optoelectronic properties and has attracted much attention. In this paper, the elastic properties of two-dimensional Janus ZrXY (X/Y = Cl, Br, and I, X ≠ Y) are studied by first principles, including elastic parameters, such as elastic tensor components, Young's modulus, Poisson's ratio, and stability. Research has found that the lattice parameters of two-dimensional Janus ZrXY are still influenced by the atomic radius. The Janus structure shows excellent dynamic stability both before and after its construction. Based on the elastic theory, the mechanical stability of the two-dimensional Janus ZrXY was proved indirectly. After constructing the two-dimensional Janus ZrXY structure with different planes, the elastic tensor component increases to a certain extent, and Young's modulus and Poisson's ratio increase, but the anisotropy of Young's modulus and Poisson's ratio decreases significantly. [ABSTRACT FROM AUTHOR]

High-entropy rare earth zirconates (RE 2 Zr 2 O 7) have attracted significant research attention for thermal barrier coatings (TBCs) application due to their superior performance. However, currently used high-entropy RE 2 Zr 2 O 7 shows only the modest improvements, thus limiting their overall performance enhancement. Therefore, novel high-entropy RE 2 Zr 2 O 7 (La 0.2 Nd 0.2 Gd 0.2 Er 0.2 Yb 0.2) 2 Zr 2 O 7 (HEC) was synthesized in this study by chemical co-precipitation method, which was characterized by dual-phase and significant differences in ionic radius and atomic mass. Compared with single-component RE 2 Zr 2 O 7 (RE = La, Nd, Gd, Er, and Yb) ceramics, HEC demonstrates significantly superior performance, including higher hardness (11.705 GPa), fracture toughness (1.693 MPa m1/2), and thermal expansion coefficient (11.1926 × 10−6/K, 1400 °C), and lower thermal conductivity (1.33–1.43 W/(m•K), 26–1000 °C). The comprehensive performance improvement can be attributed to the high-entropy effect, dual-phase nature, and significant differences in ionic radius and atomic mass. This study provides valuable insight into the development of high-entropy RE 2 Zr 2 O 7 and suggests their significant potential in TBCs. [ABSTRACT FROM AUTHOR]

Solutes segregating at the grain boundary (GB) have a significant influence on the mechanical and chemical properties of steel. In this study, the segregation effects of Si, P, and S on γ-Fe ∑5 (210)[001] GB were systematically analyzed with solution energy, segregation energy, and tensile tests by using a first principles calculation. Si, P, and S are preferred to segregate at substitutional sites in the first layer near the GB. The variation in atomic configuration and electron distribution were investigated by the analysis of bond lengths, charge density, charge density difference, and density of states (DOS), which is caused by the atomic size and electronegativity of solute atoms. Through tensile tests, it was found that Si has a strengthening effect on GB, while P and S exhibit embrittlement effects at low concentration. As the concentration of solutes increase, the segregation sites of P are different from the others owing to the tendency to form Fe3P. The exhibited embrittlement effect is mitigated at first and then aggravated. However, in both cases Si and S show aggravating embrittlement effects on GB cohesion, while the effect of Si changes from strengthening to embrittlement. This work provides comprehensive insights into the effects of Si, P, and S, which will be a useful guidance in steel design. [ABSTRACT FROM AUTHOR]

Design and development of advanced electrocatalysts with high performance and low Pt consumption are crucial for reducing the kinetic energy barrier of the cathode oxygen reduction reaction (ORR) and improving the efficiency of proton exchange membrane fuel cells (PEMFC). In this study, we demonstrate a Pb-modulated PtCo system for efficient ORR, in which the inclusion of Pb in ternary alloys induces dislocation defects due to the significant difference in atomic radius. Dislocation-PtCoPb was confirmed to exhibit significantly higher ORR activity and stability in acidic ORR. In practical PEMFC applications, it outperforms the corresponding commercial Pt/C with a mass activity of 0.58 A ⋅ mg Pt − 1 , making it a promising alternative to state-of-the-art Pt-based catalysts. The combination of experimental results and density functional theory (DFT) calculations offers valuable atomic-level insights into the dislocation structures. Pb with a larger atomic radius is located in the lattice stretching region below the dislocation slip plane, forming a structure similar to a Cottrell atmosphere, which reduces the dislocation energy and puts the system in a lower energy state. The Cottrell atmosphere pins the dislocation structure and stabilizes the ternary alloy. By adjusting the amount of added Pb, a moderate level of dislocation density induces a tuned strain effect, thereby enhancing the electrocatalytic mechanism by optimizing the electronic structure of the alloy surface and the adsorption and desorption of oxygen species. This work provides valuable insights into the design and development of lattice dislocation defect structures to trigger strain effects for improving ORR performance. [ABSTRACT FROM AUTHOR]

The topological and chemical short-range ordering (TSRO and CSRO) of Pd82Ge18 amorphous alloys prepared by the single-roll liquid quench method were analyzed using a combination of anomalous X-ray scattering and reverse Monte Carlo (RMC) simulation. The degree of development of TSRO and CSRO in the amorphous structure model made with the RMC simulation (RMC model) was evaluated by comparison with the dense random packing model (DRP model) calculated using metallic and covalent atomic radii. In the RMC model, a shortening of the Pd--Ge nearest neighbor correlation and a decrease in the coordination number around Ge were observed. Voronoi polyhedral analysis was performed to evaluate the local geometrical structure around the Pd and Ge atoms. Although the DRP structure can reasonably approximate the local structure around the Pd atoms, the TTP structure corresponding to the local structure in crystalline Pd2Ge develops around the Ge atoms as a characteristic TSRO. However, the preferential coordination of Pd atoms around Ge, which is a CSRO associated with the TTP structure in the crystalline phase, was not observed. These results indicate that strong CSRO does not necessarily accompany the TTP structures in metal-semimetal amorphous alloys. [ABSTRACT FROM AUTHOR]

Nb can effectively enhance the strength of steel through precipitation strengthening. However, the micro-scale effects of Nb in steel, especially the atomic-scale mechanisms at high temperatures, have been rarely studied. In this study, we established Fe–C and Fe–C–Nb system models using LAMMPS to explore the effects of Nb at high temperatures (1050 °C to 1200 °C) and to provide theoretical insights for the design of Nb-containing high-strength steels. The results demonstrated that Nb can significantly increase the kinetic energy of C and Fe atoms at high temperatures. In addition to the significant increase in the diffusion coefficient of atoms, the grain size also increased at the corresponding temperature, and the upper temperature limit of the segregated clusters formation was reduced. The atomic clusters formed in the simulated system were primarily composed of C atoms, with Nb atoms dispersed throughout the system. In comparison to the system without Nb, as the temperature increased, the size of the atomic clusters in the Fe–C–Nb system decreased instead of increased, indicating that Nb inhibited the growth of atomic clusters. Through tracking labeled atoms, it was found that once stable atomic clusters were formed, some atoms within the clusters underwent a cyclic process of escaping, being captured, re-escaping, and being recaptured. Through tracking labeled atoms, it was found that once stable atomic clusters were formed, some atoms within the clusters underwent a cyclic process of escaping, being captured, re-escaping, and being recaptured. Furthermore, atomic exchange occurred between closely approaching clusters. These migration mechanisms of atoms were the fundamental reason for the size stability of the clusters. [ABSTRACT FROM AUTHOR]

The effects of rare earth elements (Ce and Y) additions with the same content (0.3 wt.%, mass fraction) on microstructure evolution and mechanical properties of the Al-11.0Zn-3.1Mg-1.22Cu-0.1Sr-0.2Zr-0.1Ti alloy (base alloy) were investigated. The addition of Ce and Y refined the grain size and led to aging precipitates, which were dominated by the fine and compactly distributed GP (Guinier Preston) zones and the formed η′ (MgZn2) phase, improving the tensile properties of the alloy. The Ce-containing alloy possessed the highest tensile strength and elongation of 768.5 MPa and 8.0%, respectively. Meanwhile, the large atomic radius and low electronegativity of Ce and Y led to the discontinuous distribution of grain boundary precipitates (GBPs) and the broadening of the precipitate-free zones (PFZs) in the alloys, resulting in the improvement of intergranular corrosion resistance (IGC) of the rare earth modified alloys compared with the base alloy, with the best results for the Y-containing alloys. [ABSTRACT FROM AUTHOR]

The diffusion behavior of Cu/Ni, Cu/Ni-2.0 Al-6.5 Co-1.5 Cr, and Cu/Ni-21.0 Cr-9 Fe diffusion couples was studied by combining solid–solid single-phase diffusion couples and a numerical inverse method at 1273 K. The composition-dependent interdiffusion coefficients were determined from the concentration profiles measured by electron probe microanalysis and were validated. The order of interdiffusion coefficients in the CuNiAlCoCrFe system is D ~ CrCr Ni > D ~ AlAl Ni > D ~ FeFe Ni > D ~ CoCo Ni > D ~ CuCu Ni . The order of impurity diffusion coefficients of Al, Co, Cr, Fe, and Ni in Cu was also extrapolated from interdiffusion coefficients on the boundary, and the influence of atomic size on impurity diffusion coefficients was analyzed. [ABSTRACT FROM AUTHOR]

The diffusion and site occupation of hydrogen in the monohydride phase (β phase) of the V1−x−yCrxMoy–H (x + y ≤ 0.15) system have been studied by means of proton nuclear magnetic resonance. The β phase has a body centered tetragonal (BCT) structure and hydrogen atoms occupy the octahedral (Oz) sites along the c-axis. Cr has a smaller atomic radius than V but Mo has a larger one, resulting in no obvious change in the unit cell volume of the BCT lattice by substitution of both Cr and Mo for a part of V, although the multiple metal elements of V, Cr, and Mo induce lattice strain and distortion. The temperature dependence of 1H spin-lattice relaxation time has demonstrated that the substitution of both Cr and Mo offsets the change in the activation energy for hydrogen diffusion EH for the Oz sites, while our previous study has indicated that Cr increases EH and Mo decreases that. The diffusion behavior of hydrogen is explained by the dimension of the interstitial sites attributing to the weighted mean atomic radius of the substitutional metal elements, which is independent of their affinities for hydrogen and the lattice strain. [ABSTRACT FROM AUTHOR]

Crystal-glass nanocomposites with the synergy of high strength and exceptional ductility are promising for future applications in micro-electromechanical systems. Deformation behaviors of crystal-glass nanocomposites are governed by the formation and propagation of their plastic deformation carriers, namely, dislocations in the crystalline phase and strain-activated atomic clusters (e.g., shear transformation zones and shear bands) in the glassy phase. Yet, it is challenging to unveil the size effect of a glassy domain on the propagation of plastic deformation carriers in crystal-glass nanocomposites. To clarify the above issue, in this work, we perform molecular dynamics simulation on simple configurations fabricated by embedding a series of cylinder glass domains with different radii into the single-crystal matrix. Their stress–strain response and microstructures, especially the deformation carriers in the two phases evolving with the applied compressive strain, are quantitively analyzed. The average shear strain of glassy atoms is found to significantly decrease with the increased glassy domain volume, accordingly alleviating the strain localization in the glassy phase. The formation and propagation of strain-activated atomic clusters are also suppressed by enlarging the glassy domain volume due to the lowered shear strains sustained by glassy atoms. Moreover, dislocation densities in the crystalline matrix also decrease in the configuration with a larger-volume glassy domain, which can be ascribed to the enhanced dislocation absorption effect from the amorphous-crystal interfaces. This work indicates that the mechanical properties of multi-phase nanocomposites can be improved by rationally optimizing the phase contents and provides new knowledge on designing high-performance nanocomposites. [ABSTRACT FROM AUTHOR]

As a semiconductor with a wide bandgap, 4H silicon carbide (4H-SiC) has considerable potential for high-temperature and high-power devices. It is widely established that p-type 4H-SiC is formed predominantly by doping Al. Although Al diffusion in 4H-SiC is often negligible at low temperatures due to the tight bonding of Al in 4H-SiC, the diffusion coefficient of Al dramatically rises when the temperature is rather high. While diffusion is the most fundamental physical processes, the diffusion mechanism of Al in 4H-SiC remains unknown. Due to the large atomic radius of Al relative to the host Si/C atoms and the fact that Al occupies the Si lattice in 4H-SiC, the diffusion of Al is typically mediated by point defects such as vacancies and self-interstitials. We now investigate the diffusion of Al in 4H-SiC using first-principles calculations and compare the activation energy of Al diffusion mediated by carbon vacancies (VC) to that of Al diffusion mediated by Si interstitials (Sii). It is found that Al diffusion is actually a Sii-mediated process, in which a nearby Sii first kicks a substitutional Al atom to an interstitial site. The kicked-out Al then spreads via interstitial sites. The diffusion coefficient is calculated, which is comparable to experimental results. [ABSTRACT FROM AUTHOR]

To quickly screen for single-phased multi-principal-element materials, a so-called entropy forming ability (EFA) parameter is sometimes used as a descriptor. The larger the EFA, the larger is the propensity to form a single-phase structure. We have investigated this EFA descriptor with atomic relaxations in special-quasi-random structures and discovered that the EFA correlates inversely with the lattice distortion. Large effective atomic size differences lead to multi-phase compounds, and little size differences to single-phase compounds. Instead of configurational entropy, we therefore demonstrate the applicability of the Hume-Rothery rules to phase stability of solid solutions even in compositionally complex ceramics. [ABSTRACT FROM AUTHOR]

Effective passivation of defects at the buried interface between the perovskite absorber and hole‐selective layer (HSL) is crucial for achieving high performance in inverted perovskite solar cells (PSCs). Additionally, the HSL needs to possess compact molecular packing and intrinsic photo‐ and thermo‐stability to ensure long‐term operation of the devices. In this study, a novel MeO‐BTBT‐based self‐assembled monolayer (SAM) is reported to serve as an efficient HSL in inverted PSCs. Compared to the well‐established carbazole‐containing SAM MeO‐2PACz, MeO‐BTBT has flat and more extended conjugation with large atomic radius of the sulfur atom. These induce stronger intermolecular interactions to enable more ordered and compact SAM to be formed on indium–tin oxide (ITO) substrates. Meanwhile, the sulfur atoms in MeO‐BTBT can coordinate with Pb2+ ions to passivate the defects at the buried interface of perovskite absorber. The derived perovskite films show both high photoluminescence (PL) quantum yield (13.2%) and a long lifetime (7.2 µs). The PSCs based on MeO‐BTBT show a PCE of 24.53% with an impressive fill factor of 85.3%. The PCEs of MeO‐BTBT‐based devices can maintain ≈95% of their initial values after being aged at 65 °C for more than 1000 h or continuous operation under 1‐sun illumination. [ABSTRACT FROM AUTHOR]

Heteroatom-doping of carbonaceous materials and (nano)structures permits alteration of their fundamental physicochemical properties and thus amplifies the range of their potential applications. While nitrogen-doping dominated this research area, doping and co-doping with other non-metal and metal elements proved to be equally efficient strategies to tune carbonaceous materials' characteristics. Heavier chalcogens are considered atypical carbon dopants due to their large atomic radii, high polarizability, and electronegativity comparable to that of carbon. Se-doped carbons are much less common than their S-doped counterparts, yet recently, they appeared as attractive functional materials for a range of sustainable technologies. This review depicts progress in Se-doped and co-doped carbonaceous materials from 2012 to the present. The report is divided into three major parts: first, the versatile chemistry of selenium and the significance of Se-doping is presented, followed by a variety of preparation methods, and finally, prominent examples of advanced applications in the fields of heterogeneous (electro)catalysis, energy conversion/storage, and pollutant neutralization. [ABSTRACT FROM AUTHOR]