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Calcium–magnesium–alumina–silicate (CMAS) corrosion has attracted special attention in the thermal barrier coating (TBC) field. At high temperatures, when CMAS melts, it adheres to the coating surface and penetrates the interior, severely destroying the TBC. In this study, a promising CMAS-phobic and infiltration-inhibiting material, GdPO4, on which molten CMAS is difficult to wet and penetrate, was proposed. These desirable attributes are explained by analyzing the material characteristics of GdPO4 and its interfacial reaction with CMAS. GdPO4 is demonstrated to have low surface energy, making it difficult for molten CMAS to wet and adhere to the surface. When in contact with molten CMAS, a double-layer structured reaction layer consisting of an acicular upper sublayer and a compact lower sublayer is formed on the GdPO4 surface, which can effectively impede molten CMAS spreading and penetration. First-principles calculation results revealed that the reaction layer has low surface energy and low adhesion to CMAS, which are favorable for molten CMAS phobicity. Additionally, the formation of the reaction layer increases the viscosity of the molten CMAS, which can increase melt wetting and penetration. Hence, GdPO4, which exhibits excellent CMAS-phobicity and infiltration-inhibiting ability, is a promising protective layer material for TBCs against CMAS adhesion and attack.

The Cu–Cr–Zr–Nb alloy bars were prepared by vacuum melting, hot forging, solution treatment, and drawing. The effects of aging processes on the microstructure, texture, mechanical properties and electrical conductivity of the alloy were studied, and the precipitation kinetics was analyzed. Besides, the effect of adding Nb to the Cu–Cr–Zr alloy was simulated by the first-principles calculation. The results showed that when the aging temperature increased from 400 °C to 460 °C, Cube texture and Brass texture were transformed into Copper texture. The Cu–Cr–Zr–Nb alloy exhibited superior comprehensive properties such as a hardness of 84.3 HRB, a tensile strength of 520 MPa, an elongation of 19.0 %, and an electrical conductivity of 83.5 International Annealed Copper Standard (%IACS) after being aged at 460 °C for 4 h. The precipitation kinetics and electrical conductivity equations under different aging temperatures were established, and the precipitation activation energy of 24 kJ/mol was obtained. Moreover, the precipitation process of the alloy was also described by the Avrami empirical equation. It was found that the reaction mechanism of the alloy changed from nucleation and growth to one-dimensional diffusion as the aging temperature increased from 400 °C to 520 °C. It was also confirmed that Nb and Cr formed the Cr2Nb compound according to the first-principles calculation.

To effectively replace diseased and damaged thoracic vertebrae, a series of three-dimensional (3D) printed titanium (Ti) alloy (Ti6Al4V) thoracic fusion cages with varying volume ratio of reinforced scaffolds are designed, and their structure-function relationships are investigated systematically. It is demonstrated that the mechanical strength of fusion cage is gradually enhanced as the scaffold volume increases, which may be attributed to its textural transformation from α phase to β phase. The compressive, shear, and fatigue of fusion cages successfully attain the International Organization for Standardization (ISO 23089), when the scaffold volume ratio exceeds 15%. Furthermore, the biomechanical analyses, including stress distributions and subsidence in flexion, extension, axial rotation, and lateral bending sections of fusion cages, further shed light on their potential clinical applications. This work deeply deciphers the intrinsic connection between biomechanical property and material texture of the thoracic fusion cages, offering valuable insights into their strengthening mechanism, which providing a guidance for the precise design and quick synthesis of other 3D-printed Ti6Al4V implants.

The βʹ-Cu4Ti phase is the major strengthening precipitate in Cu–Ti alloys. Previous research indicates that destabilization of the βʹ-Cu4Ti phase leads to dissolution of Ti atom from precipitates into the Cu matrix. In the present work, Sc was chosen to be alloying elements in Cu–Ti alloys, since stabilization of the βʹ-Cu4Ti phase could be enhanced by formation of βʹ-Cu4(Ti,Sc) phase. Experimental characterization combined with first-principles calculations were used to evaluate the effect of Sc addition. It was found that the bonding between Ti and Sc atoms in the same sublattice of βʹ-Cu4Ti phase increases the diffusion barrier of Ti atoms, and thus dissolution of the βʹ-Cu4Ti phase and further nucleation of the β-Cu4Ti phase were hindered.

In this work, the mechanical properties of Mo3NiB3 and Mo2NiB2 phases in Mo-Ni-B cermets were studied. The first-principles calculation results demonstrate the thermodynamic and mechanical stability of both Mo3NiB3 and Mo2NiB2. Among them, Mo2NiB2 shows superior stability and toughness compared to Mo3NiB3. On the other hand, the Young’s modulus and hardness values of Mo3NiB3 are higher than those of Mo2NiB2. Mo3NiB3 exhibits enhanced isotropy and stronger covalent bonding properties, as confirmed by DOS and Mulliken analysis. Further research shows that Mo3NiB3 has brittleness (B/G = 1.586) and high Vickers hardness (22.3 GPa), indicating its potential use as a wear-resistant material. To validate the accuracy of the theoretical calculations, Mo3NiB3 and Mo2NiB2 cermets were fabricated through vacuum hot pressing sintering, followed by comprehensive analysis of their microstructure and mechanical properties. Specifically, the experimentally measured compressive strength and hardness values of Mo3NiB3 (3213.2 MPa and 3264.2 HV0.3, respectively) were closely matched by the theoretical predictions. Notably, these experimental findings are in good agreement with the theoretically calculated values. This investigation provides reference value for a more in-depth analysis of the mechanical properties of Mo-Ni-B cermets, provides a theoretical and practical basis for its application in the field of materials, and promotes the development of Mo-Ni-B cermets materials.

Two-dimensional heterojunction materials show great potential for a wide range of applications with their tunable properties, such as versatility and low-dimensional confinement effects. The electronic structure, transport, and optical properties of Janus WSSe/g-GeC heterojunctions are investigated in-depth using density functional theory combined with a nonequilibrium Green's function approach. The results show that the electronic properties of Janus WSSe/g-GeC heterojunction materials can be effectively tuned by applying vertical and biaxial strain. In particular, when a biaxial strain of ±10% is applied, it can transform the heterojunction from semiconductor properties to metallic properties. In addition, we found that a Janus WSSe/g-GeC heterojunction exhibits excellent optical properties with a strong absorption peak in the visible region. In this heterojunction-based PIN junction, considerable photocurrents are generated in the visible range, especially in the region of 1.7 to 3.1 eV, where significant photocurrent density peaks appear, and the vertical strain can effectively modulate the photocurrent density peaks. In addition, a Janus WSSe/g-GeC heterojunction-based device exhibits excellent performance with a high current switching ratio of 1011 at the biaxial strain of ±10%, showing perfect diode behavior. In summary, by tuning the applied strain, its electronic properties can be effectively tuned and exhibit excellent optical response. Janus WSSe/g-GeC heterojunction materials have great potential for optoelectronic and switching devices. These findings provide important references and guidance for further development of practical applications based on WSSe/g-GeC heterojunctions. [ABSTRACT FROM AUTHOR]

Recently, the application of two–dimensional (2D) piezoelectric materials has been seriously hindered because most of them possess only in–plane piezoelectricity but lack out–of–plane piezoelectricity. In this work, using first–principles calculation, by atomic substitution of penta–graphene (PG) with tiny out–of–plane piezoelectricity, we design and predict stable 2D X–PG (X = Si or Ge) semiconductors with excellent in–plane and out–of–plane piezoelectricity and extremely high in–plane hole mobility. Among them, Ge–PG exhibits better performance in all aspects with an in–plane strain piezoelectric coefficient d11 = 8.43 pm/V, an out–of–plane strain piezoelectric coefficient d33 = −3.63 pm/V, and in–plane hole mobility μh = 57.33 × 103 cm2 V−1 s−1. By doping Si and Ge atoms, the negative Poisson's ratio of PG approaches zero and reaches a positive value, which is due to the gradual weakening of the structure's mechanical strength. The bandgaps of Si–PG (0.78 eV) and Ge–PG (0.89 eV) are much smaller than that of PG (2.20 eV), by 2.82 and 2.47 times, respectively. This indicates that the substitution of X atoms can regulate the bandgap of PG. Importantly, the physical mechanism of the out–of–plane piezoelectricity of these monolayers is revealed. The super–dipole–moment effect proposed in the previous work is proved to exist in PG and X–PG, i.e., it is proved that their out–of–plane piezoelectric stress coefficient e33 increases with the super–dipole–moment. The e33–induced polarization direction is also consistent with the super–dipole–moment direction. X–PG is predicted to have prominent potential for nanodevices applied as electromechanical coupling systems: wearable, ultra–thin devices; high–speed electronic transmission devices; and so on. [ABSTRACT FROM AUTHOR]

[Display omitted] Researchers are interested in single-atom catalysts with atomically scattered metals relishing the enhanced electrocatalytic activity for nitrogen reduction and 100 % metal atom utilization. In this paper, we investigated 18 transition metals (TM) spanning 3d to 5d series as efficient nitrogen reduction reaction (NRR) catalysts on defective 2D SiP V layered structures through first-principles calculation. A systematic screening identified Mo@SiP V , Nb@SiP V , Ta@SiP V and W@SiP V as superior, demonstrating enhanced ammonia synthesis with significantly lower limiting potentials (−0.25, −0.45, −0.49 and −0.15 V, respectively), compared to the benchmark −0.87 eV for the defective SiP. In addition, the descriptor Δ G *N was introduced to establish the relationship between the different NRR intermediates, and the volcano plot of the limiting potentials were determined for their potential-determining steps (PDS). Remarkably, the limiting voltage of the NRR possesses a good linear relationship with the active center TM atom Ɛ d , which is a reliable descriptor for predicting the limiting voltage. Furthermore, we verified the stability (using Ab Initio Molecular Dynamics − AIMD) and high selectivity (U L (NRR)- U L (HER) > -0.5 V) of these four catalysts in vacuum and solvent environments. This study systematically demonstrates the strong catalytic potential of 2D TM@SiP V (TM = Mo, Nb, Ta, W) single-atom catalysts for nitrogen reduction electrocatalysis. [ABSTRACT FROM AUTHOR]

The physical properties of perovskite-type materials are sensitive to their chemical composition and crystallographic structure, which makes them highly versatile for various advanced technological applications. In this theoretical study, density functional theory (DFT) is employed to investigate the electronic properties of the perovskite-like material CaTiO3, focusing on the substitution of Ti4+ with the magnetic transition metal Cr4+. The results reveal a systematic increase in the effective magnetic moment and a gradual decrease in the bandgap with increasing Cr4+ content in the CaTi1−xCrxO3 system (x = 0.0, 0.25, 0.5, 0.75, 1.0). The interactions between electronic orbitals associated with Ti-O-Cr inter-octahedral bonds modify the magnetic response of the material, leading to hybridizations between valence and conduction states that alter its semiconductor character. This tunability in electronic and magnetic properties underscores the potential of these materials for applications in spintronics. This study offers novel insights into the design of new magnetic semiconductor materials with tailored functionalities, contributing to the development of next-generation spintronic devices. [ABSTRACT FROM AUTHOR]

The promise of using 2D materials for hydrogen storage has broad prospects, ascribe to their significant specific surface area and lightweight properties. In this work, the hydrogen storage capability and reversible storage mechanism of 2D penta-SiCN material are investigated based on the first-principles computational method. Thermal stability of penta-SiCN is calculated by the ab-initio molecular dynamics (AIMD) simulation and root-mean-square displacement (RMSD) algorithm. It has been found that penta-SiCN is thermodynamically stable even after adsorbing hydrogen molecules. Taking into account the benchmarks of average and continuous adsorption energies of the adsorption systems, a pristine 2 × 2 × 1 penta-SiCN substrate has the ability to adsorb up to 26H 2 molecules, which results in a maximum hydrogen storage capacity of 10.80 wt%. According to the semi-empirical calculation method that based on the thermodynamic analysis, the penta-SiCN adsorption system has a high reversible hydrogen storage capacity of 9.57 wt% within the adsorption and desorption application working conditions. The results proposed in this study demonstrates that penta-SiCN exhibits considerable promise for hydrogen storage with its substantial hydrogen storage capacity, exceptional reversibility, and eco-friendly characteristics. [Display omitted] • Pristine penta-SiCN is a promising material for hydrogen storage. • Theoretical predictions by combining DFT and a semi-empirical calculation method. • The gravimetric densities of penta-SiCN can reach 10.80 wt%. • The penta-SiCN has a high reversible hydrogen storage capacity of 9.57 wt% within the adsorption and desorption working environment. [ABSTRACT FROM AUTHOR]

Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy (WtE) incineration processes. This study aims to investigate the influence of hematite surface oxygen point defects on the formation of environmentally persistent free radicals (EPFRs) from phenolic compounds based on the first-principles calculations. Two oxygen-deficient conditions were considered: oxygen vacancies at the top surface and on the subsurface. Our simulations indicate that the adsorption strength of phenol on the α-Fe 2 O 3 (0001) surface is enhanced by the presence of oxygen vacancies. However, the presence of oxygen vacancies has a negative impact on the dissociation of the phenol molecule, particularly for the surface with a defective point at the top layer. Thermo-kinetic parameters were established over a temperature range of 300–1000 K, and lower reaction rate constants were observed for the scission of phenolic O-H bonds over the oxygen-deficient surfaces compared to the pristine surface. The negative effects caused by the oxygen-deficient conditions could be attributed to the local reduction of Fe III to Fe II , which lower the oxidizing ability of surface reaction sites. The findings of this study provide us a promising approach to regulate the formation of EPFRs. [ABSTRACT FROM AUTHOR]

Context: Silicon carbide nanowires (SiCNWs) are considered a promising alternative material for application in lithium-ion batteries, with researchers striving to develop new electrode materials that exhibit high capacity and high charge/discharge rate performance. To gain a deeper understanding of the application of SiCNWs in semiconductor material science and energy supply fields, we investigated the effects of nanoscale and surface lithiation on the electrical and mechanical properties of SiCNWs grown along the [111] direction. First-principles calculation was used to study their geometries, electronic structures, and associated electrochemical properties. Herein, we considered SiCNWs with full hydrogen passivation, full lithium passivation, and mixed passivation at different sizes. The formation energy indicates that the stability of SiCNWs increases with the increasing diameter, and the surface-lithiated SiC nanowires (Li-SiCNWs) are found to be energetically stable. The mixed passivated SiCNWs exhibit the properties of indirect band gap with the increase of lithium atoms on the surface, while the fully lithium passivated nanowires exhibit metallic behavior. Charge analysis shows that a portion of the electrons on the lithium atoms are transferred to the surface atoms of the nanowires and electrons prefer to cluster more near the C atoms. Additionally, Li-SiCNWs still have good mechanical resistance during the lithiation process. The stable open-circuit voltage range and theoretical capacity of these SiCNWs indicate their suitability as anode materials. Method: In this study, Materials Studio 8.0 was used to construct the models of the SiCNWs. And all the density functional theory (DFT) calculations were performed by the Vienna ab initio Simulation Package (VASP). The self-consistent field calculations are performed over a Monkhorst–Pack net of 1 × 1 × 6 k-points. The energy convergence criteria for the self-consistent field calculation were set to 10−5 eV/atom with a cutoff energy of 400 eV. [ABSTRACT FROM AUTHOR]

Mercury is a toxic heavy metal, and mercury emitted in various forms in production and life poses a certain degree of threat to ecology and human health. Therefore, it is of great importance to find highly effective mercury adsorbents. Based on the first-principles calculation method of density functional theory, the adsorption and oxidation mechanism of mercury on Ti2NO2（MXene） and Ti2NO2 with an oxygen vacancy(Ov-Ti2NO2) defect was studied. The calculation results show that the adsorption of Hg0 on the surface of Ti2NO2 is physical adsorption and the adsorption on the surface of Ov-Ti2NO2 is chemical adsorption. The presence of oxygen vacancies on the surface of Ti2NO2 can improve the interaction between HgO and Ov-Ti2NO2, thereby increasing the adsorption energy by 116 kJ/mol. The reaction barrier of Hg0 oxidation to HgO on the surface of Ov-Ti2NO2 is 92.55 kJ/mol, which is smaller than the energy barrier of its oxidation reaction on the surface of Ti2NO2（101.42 kJ/mol), which is more conducive to the oxidation of Hg0. In addition, the energy required for the desorption of HgO on Ov-Ti2NO2 surface is 226.18 kJ/mol, which is much higher than that of 110.49 kJ/mol on Ti2NO2 surface, indicating that the Ov-Ti2NO2 has better control ability of product HgO than Ti2NO2, which can inhibit secondary pollution caused by HgO desorption. [ABSTRACT FROM AUTHOR]

The misuse of metronidazole（MNZ） has caused serious pollution of the water environment. In this paper, the adsorption effects of MNZ on single-walled carbon nanotube（CNT） and Fe doped carbon nanotube（Fe-CNT） were studied by first-principles calculation. The adsorption structure, adsorption energy, electron orbital, charge transfer and state density of single-walled CNT and Fe-CNT and MNZ were calculated respectively. The results show that the original CNT has a weak adsorption effect on MNZ, while the interaction between Fe-CNT and MNZ is significantly enhanced. Therefore, Fe-CNT is expected to be candidates for adsorbing the water contaminant MNZ. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We present a computational study of the electrochemical oxygen reduction reaction on single metal catalysts embedded in nitrogen-doped graphene, namely, TM-N4-C (TM＝Fe, Co), using density functional theory calculations combined with the effective screening medium method and the reference interaction site model. We systematically investigated the roles played by solvent, electrolyte (pH), and electrode potential in the electrochemical oxygen reduction reaction on TM-N4-C. Furthermore, by performing constant-potential calculations, we were able to obtain the limiting potentials/overpotentials, in better agreement with the experimental values than those obtained with the constant-charge (neutral) calculations, demonstrating the importance of the constant-potential calculations of the electrochemical reactions. [ABSTRACT FROM AUTHOR]

Environmental barrier coatings are critically needed in the future to safeguard SiC-based ceramic matrix composites (SiC CMCs) used in gas turbines. Element doping of rare earth monosilicates could further improve the properties of the coating. The crystal structure, elastic properties, and resistance to water vapor corrosion of Yb2SiO5 and YbRESiO5 (where RE = Sc, Y, Eu, Gd, Ho, Tm, Lu) were examined in this study using first-principles calculations. When RE is Yb, the material is Yb2SiO5. Based on the outcomes of the calculation, we prepared YbRESiO5 (RE = Sc, Yb, Eu) and studied the thermodynamic properties. The findings show that YbReSiO5's resistance to water vapor corrosion is as follows: YbLuSiO5 < YbEuSiO5 < YbGdSiO5 < YbYSiO5 < Yb2SiO5 < YbTmSiO5 < YbHoSiO5 < YbScSiO5. YbScSiO5 has a lower unit cell volume, average Re-O bond length, and thermal expansion coefficient than Yb2SiO5, while YbEuSiO5 has the reverse pattern. Moreover, of the eight materials, YbScSiO5 has the greatest elastic modulus and lattice distortion. After doping with Eu, YbEuSiO5 exhibits a decrease in thermal conductivity by nearly thirty percent compared to Yb2SiO5, due to the formation of oxygen vacancies. The development of environmental barrier coating materials may benefit from these discoveries. [ABSTRACT FROM AUTHOR]

We have theoretically explored the mechanism of selective growth of ordered 2D C x N y compounds on various epitaxial substrates, which can be achieved under distinct chemical potential windows by establishing the substrate mediated thermodynamic phase diagrams as well as the kinetics pathways. Accordingly, the optimal experimental conditions, e.g., the temperature and partial pressure of feedstock, are also suggested. [Display omitted] Two-dimensional (2D) ordered carbon–nitrogen binary compounds (C x N y) show great potential in many fields owing to their diverse structures and outstanding properties. However, the scalable and selective synthesis of 2D C x N y compounds remain a challenge due to the variable C/N stoichiometry induced coexistence of graphitic, pyridinic, and pyrrolic N species and the competitive growth of graphene. Here, this work systematically explored the mechanism of selective growth of a series of 2D ordered C x N y compounds, namely, the g-C 3 N 4 , C 2 N, C 3 N, and C 5 N, on various epitaxial substrates via first-principles calculations. By establishing the thermodynamic phase diagram, it is revealed that the individualized surface interaction and symmetry match between 2D C x N y compounds and substrates together enable the selective epitaxial growth of single crystal 2D C x N y compounds within distinct chemical potential windows of feedstock. The kinetics behaviors of the diffusion and attachment of the decomposed feedstock C/N atoms to the growing C x N y clusters further confirmed the feasibility of the substrate mediated selective growth of 2D C x N y compounds. Moreover, the optimal experimental conditions, including the temperature and partial pressure of feedstock, are suggested for the selective growth of targeted 2D C x N y compound on individual epitaxial substrates by carefully considering the chemical potential of carbon/nitrogen as the functional of experimental parameters based on the standard thermochemical tables. This work provides an insightful understanding on the mechanism of selective epitaxial growth of 2D ordered C x N y compounds for guiding the future experimental design. [ABSTRACT FROM AUTHOR]

Transition metal (TM) single-atom catalysts (SACs) have been widely applied in photocatalytic CO2 reduction. In this work, n–p codoping engineering is introduced to account for the modulation of photocatalytic CO2 reduction on a two-dimensional (2D) bismuth-oxyhalide-based cathode by using first-principles calculation. n–p codoping is established via the Coulomb interactions between the negatively charged TM SACs and the positively charged Cl vacancy (VCl) in the dopant–defect pairs. Based on the formation energy of charged defects, neutral dopant–defect pairs for the Fe, Co, and Ni SACs (PTM0) and the −1e charge state of the Cu SAC-based pair (PCu−1) are stable. The electrostatic attraction of the n–p codoping strengthens the stability and solubility of TM SACs by neutralizing the oppositely charged VCl defect and TM dopant. The n–p codoping stabilizes the electron accumulation around the TM SACs. Accumulated electrons modify the d-orbital alignment and shift the d-band center toward the Fermi level, enhancing the reducing capacity of TM SACs based on the d-band theory. Besides the electrostatic attraction of the n–p codoping, the PCu−1 also accumulates additional electrons surrounding Cu SACs and forms a half-occupied dx2−y2 state, which further upshifts the d-band center and improves photocatalytic CO2 reduction. The metastability of Cl multivacancies limits the concentration of the n–p pairs with Cl multivacancies (PTM@nCl (n > 1)). Positively charged centers around the PTM@nCl (n > 1) hinders the CO2 reduction by shielding the charge transfer to the CO2 molecule. [ABSTRACT FROM AUTHOR]

Due to its great efficiency, the electrocatalytic nitrogen reduction reaction (NRR) presents itself as a viable and eco-friendly substitute for the traditional Haber-Bosch ammonia production process. However, it is still a formidable task to find electrocatalysts with high activity and selectivity. In this study, a series of transition metals (TM = Ti–Ni, Zr–Mo, Ru–Pd, and Hf–Pt) anchored on 1T′-dual-transition-metal dichalcogenides (1T′-d-TMDs) monolayers (TM 2 @1T′-CrCoS 4) were systematically investigated as electrocatalysts for NRR using first-principles calculations based on density functional theory. Based on a thorough examination of selectivity, high activity, and stability, Mn 2 @1T′-CrCoS 4 and Co 2 @1T′-CrCoS 4 demonstrate exceptional NRR performance. With a limiting potential of −0.11 V, Mn 2 @1T′-CrCoS 4 stood out among them in terms of catalytic activity, favoring the enzymatic pathway. Furthermore, ab initio molecular dynamics (AIMD) simulations were used to assess the dynamic stability of Mn 2 @1T′-CrCoS 4 and Co 2 @1T′-CrCoS 4. To determine the source of increased activities, the density of states (DOS), charge density difference, and crystal orbital Hamilton population analysis were used. According to our research, the 1T′-d-TMD S is a viable substrate for the development of effective NRR catalysts and offers a platform for electrocatalyst experimentation. [Display omitted] • 1T′-d-TMDs monolayers have been investigated as a new efficient electrocatalyst substitute in the electrocatalysis field. • The 1T′-CrCoS 4 with unique characteristics is potential electrocatalysis as the candidate material for NRR. • The NRR catalytic performance of TM dimer anchored on 1T′-CrCoS 4 is investigated. • The Mn 2 @1T′-CrCoS 4 exhibits excellent catalytic activity with a low limiting potential of −0.11 V. [ABSTRACT FROM AUTHOR]

As a typical penta two-dimensional material and proposed to be potentially synthesized, in this paper we built a two-probe photodetector based on the penta-BP5 monolayer, and further studied linear and elliptical photogalvanic effects in this device. It was found that produced photocurrents in the BP5 photodetectors mainly show sine relation on double times of the polarized or elliptical angle for the incident light, and the relation can be modulated by the photon energy and polarized angle. Interestingly, due to high asymmetry of the BP5 monolayer, the pristine BP5 photodetector generates very high photocurrents, which are even larger than those including vacancy- and substitution-doping, and this result further proved that asymmetry plays a decisive role in the generation of robust photogalvanic effects, instead of introducing impurities to enhance this effect. Furthermore, the linear photogalvanic effect is stronger than the elliptical photogalvanic effect, and the BP5 photodetectors for the pristine, vacancy- and substitution-doping cases have relatively high extinction ratios showing these BP5 photodetectors are all polarization-sensitive. In conclude, these results manifest great potential applications of the penta-BP5 photodetectors on high performance optoelectronics and nanoelectronic devices. [ABSTRACT FROM AUTHOR]

Delafossite CuFeO2 is widely used in the field of photocatalysis due to its narrow band gap and easy availability, while the photogenerated carriers are easy to compound due to its centrosymmetric layered structure, limiting its photocatalytic effect. In view of this, this paper focuses on another configuration of, namely β-CuFeO2, which is an intrinsic ferroelectric semiconductor with phase stability, narrow band gap, and strong polarization. We construct the [011] surface with alternating arrangement of photogenerated electron and hole generation sites, which promotes charges separation under the action of ferroelectric built-in electric field to enhance the photocatalytic performance. Based on first-principles calculations, this study identified β-CuFeO2 as a direct bandgap semiconductor with thermodynamic stability, a C-type antiferromagnetism in the magnetic ground state, and the bandgap size of 1. 37 eV, with a theoretical ferroelectric polarization intensity of 83. 46 μC/cm², which is a good photocatalyst carrier. Further, using the surface oxygen precipitation reaction (OER) as a model, unpolarized direction surfaces [100], [010] and polarized direction surfaces [001], [011] were constructed to investigate the effect of ferroelectric polarization on the OER. The results show that the surface Valance Band Maximum (VBM) redox potential of β-CuFeO2 is mostly more than the water oxidation potential (1. 23 eV) and the polarized surface is easier to form. In addition, the [011] surface with fully exposed Cu-O atoms and alternating layers of Cu, Fe atoms in the polarization direction is the most susceptible to adsorption of water molecules and has the optimal OER catalytic activity. The electronic structure analysis of the rate-determining step for the OER on the [011] surface reveals that there are two electron pockets on the *O intermediate, and one electron pocket is consumed after the reaction to produce * OOH. This is the intrinsic mechanism of the OER rate-determining step on the polarization direction [011] surface. β-CuFeO2 ferroelectric semiconductor was constructed in this work and its basic properties were calculated by theoretical simulations, and different directions of surfaces were constructed to study the effect of ferroelectric polarization on the photocatalytic OER activity, which will provide a new perspective for the design of ferroelectric photocatalysts. [ABSTRACT FROM AUTHOR]

The contents of alkali and alkaline earth metals are higher in Zhundong coal, and there are serious problems of slagging and fouling during the combustion process. Therefore, it is of great significance to reveal the mechanism of slagging and fouling in the boiler of Zhundong coal. In this paper, first-principle calculations based on density functional theory are used to study the competition mechanism of alkaline metal oxides during the combustion process in Zhundong coal by establishing the Na2O(110)/CaO(100)-SiO2(100) double-layer interface model. The results show that the bond lengths of the surface of Na2O(110) and CaO(100) with SiO2(100) after adsorption were generally lengthened and the value of bond population became smaller, which formed a stable binding energy during the reaction. The electron loss of Na is 0.05 e, the electron loss of Ca is 0.03 e, and the electron loss of Na2O is greater than that of CaO. The charge transfer on the surface of Na2O with SiO2 is obviously higher than that of CaO and the orbital hybridization on the surface of CaO with SiO2 is weaker than that on the surfaces of Na2O with SiO2. Na2O is easier to react with SiO2 than CaO. The adsorption energies on the surface of Na2O and CaO with SiO2 are −5.56 eV and −0.72 eV, respectively. The adsorption energy of Na2O is higher than that of CaO, indicating that Na2O is more prone to adsorption reactions and formation of Na-containing minerals and other minerals, resulting in more serious slagging. In addition, the XRD analyses at different temperatures showed that Na-containing compounds appeared before Ca-containing ones, and the reaction activity of Na2O is stronger than that of CaO in the reaction process. The experimental results have good agreement with the calculation results. This provides strong evidence to reveal the slagging and fouling of Zhundong coal. [ABSTRACT FROM AUTHOR]

Nowadays there is considerable interest in the photogalvanic effect in low-dimensional devices. In this work, we built a two-dimensional Bi2C-based photodetector and explored the spin-dependent photogalvanic effect under linearly polarized light and zero-bias conditions which can produce experimentally observable photoelectron flow. It was discovered that by introducing vacancies and substitution-doping into the Bi2C photodetector, the photogalvanic effect could be enhanced by 10–100 times that of a pristine photodetector, which is sufficient to be detected in experiments. Moreover, due to strong spin–orbit interactions, the Bi2C photodetector can produce very high spin polarization, even 100% full spin polarization, and pure spin current at a specific incident angle and photon energy, for example in the Bi1-vacancy Bi2C photodetector. In addition, the photon energy of incident light can regulate the produced spin photocurrent, which shows considerable anisotropy. Our results highlight the potential of the Bi2C photodetector as a versatile device in optoelectronics and spintronics applications. [ABSTRACT FROM AUTHOR]

This study investigates the structural, mechanical, optical, thermal, and electronic properties of the ionic semiconducting materials XZrS3 (X = Ca, Ba) within the framework of density functional theory (DFT). Here, the elastic constants, modulus (bulk, shear, Young's), ratios (Pugh, Poisson) and elastic anisotropy for XZrS3 (X = Ca, Ba) are studied. Furthermore, the electronic, optical, and thermal properties for XZrS3 (X = Ca, Ba) are regenerated and designed using the values obtained with Cambridge Serial Total Energy Package (CASTEP) software. The calculated lattice parameters show excellent agreement with theoretical and experimental values. The elastic stiffness constants confirm the mechanical stability of both compounds. Although XZrS3 (X = Ca, Ba) is elastically anisotropic, it has little optical anisotropy. The electronic band structures of the material exhibit direct-bandgap semiconducting behavior, with values of 1.3 eV (CaZrS3) and 1.1 eV (BaZrS3) using the generalized gradient approximation (GGA), respectively, which is ideal for solar cell (0.9–1.56 eV) and optoelectronic device applications. Bandgap values of 1.9 eV and 1.6 eV are found for CaZrS3 and BaZrS3, respectively, using the Heyd–Scuseria–Ernzerhof HSE06 functional, which is consistent with previous theoretical and experimental bandgap results. The optical properties including dielectric function, refractive index, absorption coefficient, reflectivity, and loss function are characterized using the GGA of Perdew–Burke–Ernzerhof (GGA-PBE) and HSE06 methods and are discussed in detail. Because of the relatively low Debye temperature (D), thermal conductivity of the lattice (kph), and minimum thermal conductivity (Kmin), the studied materials can be used as thermal barrier coating (TBC) materials. The capacity of heat, Debye temperature, and thermal coefficient of expansion are all computed. [ABSTRACT FROM AUTHOR]

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Inbuilt high energy band gap and resistivity cause harm to the intrinsic molybdenum trioxide (MoO3) for utilizing it directly in gas sensing and optoelectronic devices. Doping with transition metal ions can be an optimistic solution to these problems. By doping four side of modification of a material is possible. At first, doping can curtail the width of the energy band of semiconductor materials, thereby largely boosting the photo-sensitivity of the material and intensifying the light consumption that is more suitable for anti-laser devices and light source substances. The second is that doping can widen the material's band gap, which can significantly reduce the purities of the substance, improve absorbance, and make it suitable for strong interference semiconductor films and aperture materials. Third, changing the material's charge carrier density and effective mass can significantly improve conductivity. This is mostly relevant for conductive devices and photosensitive materials. Finally, changing the material's valance electron location influences the magnetic moment created by the spin of elementary particles in the entire system, allowing the magnetic characteristics of the substance to be regulated, which is especially useful for diluted magnetic semiconductor (DMS) materials. The investigation report of the structural, electrical, and optical characteristics of Cobalt (Co)-doped orthorhombic-phase MoO3 utilizing plane-wave pseudo-potential technique based on first-principles computation is presented in this paper. The computation has been executed using density a functional theory (DFT)-based CASTEP computer program with the generalized gradient approximation (GGA) together with the Perdue-Burke-Ernzerhof (PBE) exchange–correlation function. Acquired structural parameters present good consistency with the former reported experimental data. The resultant electronic band structure reveals that pure MoO3 shows an indirect energy band gap of 1.873 eV/2.312 eV whereas Co doping causes band narrowing of about 0.94 eV/1.36 eV with PBE/HSE techniques. The total and partial density of states (PDOS) have been studied comparatively, for pure and Co-doped MoO3, respectively. The absorption coefficient, loss function, reflectivity, refractive index, extinction coefficient, dielectric function, along with optical conductivity have also been determined to analyze the optical properties of Co-doped MoO3. Co-doped MoO3 offers higher conductivity while decreasing resistivity, compared to the undoped case. The present study ensures that Co-doped α- MoO3 can be competently employed as a functional material in gas sensing and optoelectronic devices. [ABSTRACT FROM AUTHOR]

This research explored the physical properties of AuMTe2 (M = Ga, In) chalcopyrite compound. We employ the full-potential linearized augmented plane wave (FP-LAPW) method in combination with the Tran-Blaha modified Becke–Johnson potential (TB-mBJ) as well as the generalized gradient approximation (GGA-PBE(96)), local density approximation (LDA) and Wu–Cohen generalized gradient approximation (WC-GGA) for the exchange–correlation potentials to analyze the structural, electronic and optical properties. The results are presented for lattice constant, bulk modulus, its pressure derivative, density of state (DOS) and optical properties. The structural and electronic outcomes obtained in this study align well with existing theoretical data. Our investigation revealed that the studied compounds exhibit a direct band gap, with average energy gaps of order of 0.281 eV for AuGaTe2 and 0.092 eV for AuInTe2 compounds, respectively. Optical properties, encompassing reflectivity R(w), absorption coefficient α(ω), refractive index n(ω), optical conductivity σ(ω), extinction coefficient k(ω) and energy loss function L(ω) are determined from real and imaginary parts of the computed dielectric function within the frameworks of the modified Becke–Johnson plus PBE-GGA(96), LDA and WC-GGA exchange–correlation potentials. The computed optical properties reveal minimal energy loss and reflectivity, alongside satisfactory absorption capability and optical conductivity within the infrared and visible spectral regions. These findings indicate potential applications in fields such as infrared absorption technologies and optoelectronic industries. This marks the initial quantitative theoretical forecast of the optical properties for these chalcopyrite compounds, necessitating experimental confirmation. [ABSTRACT FROM AUTHOR]

Annealing as an experimental means is often used to treat various electrocatalysts for improving their hydrogen evolution reaction (HER) performance. Herein, in order to investigate the effect of hydrogen annealing temperature on the HER performance of RuO 2 -based electrocatalysts, commercial RuO 2 , self-synthesized RuO 2 , and self-synthesized RuO 2 /MoO 3 composite are annealed at 150, 300, 500, and 700 °C in a hydrogen atmosphere, respectively. It's found that RuO 2 is gradually deduced at 150 °C, ultimately, completely reduced to Ru under 300 °C. Meanwhile, the content of RuO 2 at the samples surface is gradually decreases as the annealing temperature increase to 700 °C. However, for all samples, the 500 °C annealed sample shows the best HER performance in acid solutions, including the lowest over potential, the smallest Tafel slope, and the largest double-layer capacitance. We inferred that the optimal HER performance of the 500 °C annealed samples maybe attributed to their appropriate Ru/RuO 2 ratio. Density functional theory (DFT) calculations reveal that significant electron transfer across the Ru/RuO 2 interface, thereby optimizing the adsorption free energy of H on Ru and RuO 2 , ultimately resulting in Ru/RuO 2 catalyst exhibiting better HER activity than bare Ru and RuO 2. The study provides guidance on the preparation of RuO 2 -based electrocatalysts for achieving efficient hydrogen evolution. [Display omitted] • Various commercial and self synthesized RuO 2 -based catalysts have been studied. • The annealing temperature of RuO 2 -based catalysts covers a wide range of 150–700 °C. • The adsorption free energies of H on different ratio of Ru/RuO 2 were calculated. • The effect mechanism of annealing temperature on HER activity of RuO 2 was analyzed. [ABSTRACT FROM AUTHOR]

With an increasingly profound understanding of battery materials, strategies designed for interface protection have become more sophisticated. However, it is inherent that different materials used in electrodes and electrolytes tend to react with each other. To address this issue, this study proposes an "Electrode‐Electrolyte‐In‐One" (EEIO) concept, where a single energy storage material can serve as both electrode and solid‐state electrolyte (SSE) during its different ion storage stages. The EEIO materials of chloride ion batteries and fluorine ion batteries are preliminarily studied, establishing reasonable screening procedures and predicting their operational mechanisms. The analysis of Cl− and F− affinity indicates that the EEIO system in the anion storage batteries comprises the anode and SSE. Through comprehensive evaluation of ion binding capacity, phase transformation mechanism, electrical conductivity, and ion diffusion kinetic properties, several potential EEIO materials are identified. In the EEIO system, the material interface and the conductive‐insulation interface are separated, which solves the material compatibility problem between the anode and SSE. Furthermore, the EEIO system has an inherent correlation between the anode electrochemical reaction and the SSE decomposition reaction, ensuring that the electrochemical voltage of EEIO batteries never exceeds the decomposition voltage of SSE. Therefore, SSE in the EEIO battery has absolute electrochemical stability. [ABSTRACT FROM AUTHOR]

Silicon-based material is one of the most promising substitutes for commercial graphite anodes for the next generation lithium-ion batteries due to its extremely high theoretical capacity. However, the huge volume changes during the charging and discharging processes will cause rapid capacity decay and a short cycle life. Developing novel silicon-based materials requires a fundamental understanding of their properties. However, in many cases, the present experiments are incapable of completely mimicking real battery-operation conditions, and detailed information about the electrochemical mechanisms and ion and electron kinetic transport at the electrode/electrolyte interface is still ambiguous due to their complexity. First-principles calculations have become an effective method for predicting and interpreting the characteristics of electrode materials, understanding the electrochemical mechanisms at the atomic scale and delivering rational design strategies for electrode materials. In this review, the first-principles calculations of silicon-based anode materials in recent years, based on different modification strategies, are summarized. First, we introduce the diffusion kinetics of lithium ions in silicon and the mechanism of structure changes during the lithiation process. Then, typical examples of novel Si-based anodes, including 2D nanomaterials, silicide materials and coating materials based on theoretical predictions, are presented. Finally, we provide perspectives and future directions of first-principles calculations on Si-based anodes. [ABSTRACT FROM AUTHOR]

[Display omitted] Utilizing diverse material combinations in heterogeneous structures has become an effective approach for regulating interface characteristics and electronic structures. The g-C 3 N 4 /Co 3 O 4 heterostructures were fabricated by uniformly modifying Co 3 O 4 nanoparticles onto discrete clusters of g-C 3 N 4 nanosheets. Then, they were subsequently employed as positive electrode materials for assembling hybrid supercapacitors. According to the first-principles calculation, Co 3 O 4 and g-C 3 N 4 formed Co-N ionic bonds, establishing interfacial space symmetry-broken heterojunction and direct exchange and superexchange between ions at the interface and sub-interface. This resulted in a high-density spin–orbit hybrid heterogeneous polarization interface, significantly improving the quantum capacitance of heterojunction materials. Experimental results showed that the heterojunction had a specific capacitance of 2662 F g−1 at 1 A g−1. When the power density was 750 W kg−1, the energy density reached 128 Wh kg−1. Even when the power density was 16850 W kg−1, it could show an energy density of 62.5 Wh kg−1. The g-C 3 N 4 /Co 3 O 4 heterojunction could realize high energy density charge storage as the cathode material of supercapacitors. The construction of heterogeneous polarization interfaces for high-energy quantum capacitors provides a new and effective method for the energy storage field. [ABSTRACT FROM AUTHOR]

The O2 dissociative adsorption serves as a pivotal criterion for assessing the efficacy of oxygen reduction catalysts. We conducted a systematic investigation into O2 dissociative adsorption on the Pt-skin Pt3Cu(111) surface by means of the density functional theory (DFT). The computational findings reveal that the O2 adsorption on Pt-skin Pt3Cu(111) surface exhibits comparatively lower stability when contrasted with that on the Pt(111) surface. For O2 dissociation, two paths have been identified. One progresses from the t-f-b state towards the generation of two oxygen atoms situated within nearest-neighbour hcp sites. The other commences from the t-b-t state, leading to the generation of two oxygen atoms occupying nearest-neighbour fcc sites. Moreover, the analysis of the energy barrier associated with O2 dissociation indicates that O2 on the Pt-skin Pt3Cu(111) surface is more difficult to dissociate than on the Pt(111) surface. This study can offer a valuable guide for the practical application of high-performance oxygen reduction catalysts. [ABSTRACT FROM AUTHOR]

Context: Hydrogen sulfide gas poses significant risks to both human health and the environment, with the potential to induce respiratory and neurological effects, and a heightened fatality risk at elevated concentrations. This article investigates the catalytic decomposition of H2S on a Sc-Ti3C2O2 single-atom catalyst(SAC) using the density functional theory-based first-principles calculation approach. Initially, the adsorption behavior of H2S on Ti3C2O2-MXene was examined, revealing weak physical adsorption between them. Subsequently, the transition metal atom Sc was introduced to the Ti3C2O2 surface, and its stability was studied, demonstrating high stability. Further exploration of H2S adsorption on Sc-Ti3C2O2 revealed direct dissociation of H2S gas molecules into HS* and H*, with HS* binding to Sc and H* binding to O on the Ti3C2O2 surface, resulting in OH groups. Using the transition state search method, the dissociation of H2S molecules on the SAC's surface was investigated, revealing a potential barrier of 2.45 eV for HS* dissociation. This indicates that the H2S molecule can be dissociated into H2 and S with the action of the Sc-Ti3C2O2 SAC. Moreover, the S atom left on the catalyst surface can aggregate to produce elemental S8, desorbing on the catalyst surface, completing the catalytic cycle. Consequently, the Sc-Ti3C2O2 SAC is poised to be an efficient catalyst for the catalytic decomposition of H2S. Methods: The Dmol3 module in Materials Studio software based on density functional theory is used in this study. The generalized gradient approximation method GGA-PBE is used for the exchange–correlation function. The complete LST/QST and the NEB methods in the Dmol3 module were used to study the minimum energy path of the dissociation of hydrogen sulfide molecules on the catalyst surface. [ABSTRACT FROM AUTHOR]

Antigorite is the high‐temperature member of the serpentine group minerals and is broadly considered a primary carrier of water in the subducting oceanic lithosphere. It has a wavy crystal structure along its a‐axis and several polysomes with different m‐values (m = 13–24) have been identified in nature. The m‐value is defined as the number of tetrahedra in one wavelength and is controlled by the misfit between the octahedral and tetrahedral layers. The degree of misfit primarily depends on the volumes of the MgO6 octehedra and SiO4 tetrahedra within the layers, which vary as a function of pressure and temperature. However, it is not well understood which m‐values of antigorite are stable at different pressure and temperature conditions. To investigate the pressure dependence of the stability of different m‐values in antigorite, we performed first‐principles calculations for several polysomes (m = 14–19) at high pressure from 0 to 14 GPa and compared their enthalpies at static 0 K. We found that although the energy differences between polysomes are small, polysomes with larger m‐values are more stable at ambient pressure, while polysomes with smaller m‐values are more stable at elevated pressures. This suggests that the structure of antigorite in the oceanic lithosphere subducting into the deep Earth may gradually evolve into a different polysome structure than the antigorite samples observed at ambient or near‐surface pressure conditions. These changes in the m‐values are accompanied by a minor dehydration reaction. By modulating the available amount of free water in the system, antigorite polysomatism may influence the distribution of intermediate‐depth seismicity, such as the observance of double seismic zones. Plain Language Summary: Antigorite is a hydrous mineral known for being an important carrier of water into the Earth's interior and a seismicity trigger at intermediate‐depths down to ∼200 km. However, its crystal structure is complex (e.g., Uehara, 1998), and thus it is not well understood which structural variant (polysome) of antigorite is stable or dominant at high pressures and temperatures during subduction. In this study, several crystal structures of antigorite were calculated by first‐principles calculations, and their enthalpies (i.e., Gibbs free energy of a system at static 0 K) were compared to determine the stable structure as a function of pressure. The results indicate that the structure and chemical composition of antigorite likely changes under high pressure, resulting in the gradual release of water during the subduction process. As antigorite is thought to be the main trigger of seismicity in the subducting lithospheric mantle, its metasomatism may contribute to explain the reported distributions of intermediate‐depth earthquakes. Key Points: Antigorite crystal structures with various values of m (14–19) were determined by first‐principles calculation under pressureThe relative enthalpy shows that antigorite with smaller m‐values are stabilized with increased pressureAntigorite in suducting slabs may gradually dehydrate under high pressure as a result of changes to stable m‐values [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Silicon nitride (Si3N4) possesses excellent mechanical properties and high thermal conductivity, which is an important feature in many applications. However, achieving the theoretically high thermal conductivity of Si3N4 in practice is challenging. In this study, we adopted a first-principles calculation method to assess the effects of doping β-Si3N4 and γ-Si3N4 with carbon and oxygen atoms. Applying geometric structure optimization combined with calculation of the electronic phonon properties generated a stable doped structure. The results revealed that carbon and oxygen doping have little effect on the Si3N4 unit cell size, but that oxygen doping increases the unit cell volume. Energy band structure and state density calculation results showed that carbon doping reduces the nitride band gap width, whereas oxygen doping results in an n-type Si3N4 semiconductor. The findings from this study are significant in establishing a basis for targeted increase of the thermal conductivity of Si3N4. [ABSTRACT FROM AUTHOR]

The interaction between ions should be greatly modified under electronic excitation states, subsequently altering the interactions between materials. We perform a series of first-principles calculations to predict the solution and diffusion behaviors of interstitial hydrogen (H) in tungsten (W) under various electronic excitations. Qualitatively, the solution, diffusion, and trapping behaviors of H in W under various electronic excitation states are basically consistent with those in the ground state. However, it can be found that the solution energy and the migration energy barrier of H decreases as increasing the electronic temperature of system. The Pearson correlation coefficient study shows that there exists a perfect negative correlation between the lattice constant of W and H solution energy induced by lattice distortion. Besides, electronic excitations also make the binding energy of multiple H atoms decrease. That is, when the same number of H atoms are added to the vacancy, the binding energy decreases with increasing the electronic temperature of system. Based on these calculation results, we can infer that electronic excitations make dissolved H atoms more active in W system. This may, to some extent, allow dissolved H to migrate around and not aggregate so easily, thus reducing the production of H bubbles. Therefore, in quantitative terms, the electronic excited states have a certain effect on the H behavior in W.

Recent studies have found that in the absence of Cr carbide precipitation, co-segregation of Cr and other elements at the interface between α-Fe and γ-Fe can also lead to the formation of Cr-depleted zones, leading to intergranular corrosion. The study employed three-dimensional atomic probes, focused ion beams, and high-throughput first-principles calculation techniques to investigate the impact of Ni atoms on the α-Fe/γ-Fe interface of UNS S32205 duplex stainless steels. The goal was to analyze the formation of Cr-depleted zones and interface corrosion resistance. The results indicate that both Ni and Cr atoms are segregated at the interface between α-Fe and γ-Fe phases; The strong interaction between Ni and Cr atoms hinders Cr segregation at the interface and slows down the formation of Cr-depleted zones; co-segregation of Ni and Cr can improve the stability of the α-Fe/γ-Fe phase interface, reduce the generation of microcracks, and reduce the stability of Cl atom adsorption in the cracks. This establishes the theoretical basis for further suppressing the formation of Cr-depleted zones and preventing intergranular corrosion.

CoxBy alloy with high hardness and high melting point has wide range of applications in many fields because of its stable chemical property, high strength, and good thermal stability. In this work, the thermodynamic and electrical properties of five CoxBy alloys (CoB, Co2B, Co3B, Co23B6 and Co5B16), were studied and compared based on a first-principles approach. The elastic constant and related mechanical property of the binary alloys were calculated by using the energy-strain method, and the thermodynamic properties such as the Debye temperature (ΘD) and the coefficient of thermal expansion (α) within a finite temperature were calculated based on the quasi-simple harmonic Debye model. By comparing the mechanical parameters of the binary alloys, it is found that the comprehensive mechanical property of the CoB alloy is the best among the studied alloys; the state density mapping indicates that all five CoxB y alloys have good metallicity and electrical conductivity, and have some potential applications in the field of electrode materials. In Co3B and Co23B6 alloys, there is a resonance peak between the d electron orbital of Co atom and the p electron orbital of B atom, indicating that there is a significant chemical bond between Co—B.The study complements the gap of thermomechanical property parameters of CoxBy binary alloys and provides a theoretical reference for the design and application of Co based or Co—B binary alloy materials.

Solid solution effect of minor elements on mechanical and especially thermal properties of zirconium (Zr) alloys has been underexplored in previous studies. This research delves into the electronic structure, phonon, mechanics, and thermodynamics of binary solid solution Zr alloys (introduction of Sn, Cu, Al, Ge, O, N, H, and C) using density functional theory (DFT). Micro-mechanical properties are changed after doping elements, particularly for doping H as interstitials. The H-induced increase in Poisson's ratio and decrease in shear modulus, Young's modulus, and hardness should be due to H-induced enhancement in the ductility of adjacent Zr atoms. Addition-induced thermodynamic properties are discernible for substitutional and interstitial elements. High frequencies of phonons appear in the Zr alloys with interstitial solid solution, which decreases the heat capacity of the Zr alloys. Conversely, the alloys featuring a substitutional solid solution experience negligible changes in heat capacity. Grüneisen parameter associated with anharmonic interaction is a determining factor in the thermal expansion of the Zr alloys. In low phonon frequencies (≤2 THz), the more negative contribution of Grüneisen parameter leads to the lower thermal expansion of the Zr alloys with interstitial solid solution, with respect to substitutional solid solution. Deep investigation reveals that the mode of lattice vibration in the low frequency almost remains the original transverse mode of the pure Zr for interstitial solid solution. For substitutional solid solution, the atomic layer containing doping element vibrates from transversely to longitudinally. Our work helps purposefully tune the properties of novel Zr alloys through screening and adding alloying elements.

Al–Zn–Mg alloys have attracted significant interest in the automotive industry owing to their high strength and light weight. Precipitation hardening is the primary mechanism by which these alloys are strengthened, meaning the analysis of the shape, size, and fraction of the precipitates is crucial. In this study, the interfacial structure of precipitates, which influences the mechanical properties of alloys, was investigated. Aberration-corrected scanning transmission electron microscopy studies revealed the atomic structure of the unique V-shaped interface structure of the η1 precipitates, which are the most prevalent among the η precipitates produced in this alloy. The structure was investigated from an energetic perspective using first-principles calculations, which revealed that the formation of the V-shaped interface structure increased the stability through strain relaxation in both the aluminum matrix and η1. The results provide valuable insights into the formation and growth mechanisms of precipitates, paving the way for further advancements in this field.