Article
Chemistry, Multidisciplinary
Michele Pizzochero, Efthimios Kaxiras
Summary: The addition of hydrogen atom to zigzag graphene nanoribbons (ZGNRs) is investigated, revealing the role of pi-magnetism in governing the chemistry of ZGNRs and the influence of chemisorbed hydrogen atom on the pi-magnetism. The peculiar interplay between chemistry and magnetism is established at the zigzag edges of graphene.
Article
Chemistry, Physical
Henrik H. Kristoffersen
Summary: An explicit charging approach is introduced in atomic level electrochemistry modeling to account for constant potential. This method allows for calculating electrochemical reaction barriers and reproducing results from the computation hydrogen electrode (CHE) approach under constant potential conditions. The approach is used to obtain activation and adsorption free energies for proton adsorption from a static water bilayer to the Cu(111) surface.
Article
Materials Science, Multidisciplinary
Ying Li, Chi-Ho Cheung, Gang Xu
Summary: By using calculations and analysis, a complete phase diagram of body-centered silicon has been explored and a topological Luttinger semimetal state with nontrivial surface states has been discovered. The electronic properties of silicon can also be tuned to a normal insulator or topological Dirac semimetal by tiny changes.
Article
Nanoscience & Nanotechnology
M. Petrik, Yu N. Gornostyrev, P. A. Korzhavyi
Summary: The study systematically investigated the interactions of alloying elements and vacancies with coherent interfaces of the theta' phase in Al-based alloys, revealing that the presence of vacancies in the interfacial Cu layer plays a crucial role in solute-interface interactions. The solute-interface interaction energies were found to be weaker for elements with closed or empty d-electron shells compared to d-transition metals. The roles of alloying elements and interface structure in the stability of theta' phase precipitates were analyzed in terms of electronic structure and atomic size contributions to interatomic bonding.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Physical
Feina Zhai, Yun Tian, Dandan Song, Yuanjie Li, Xiaojing Liu, Ting Li, Zhaojun Zhang, Xiangjian Shen
Summary: An in-depth understanding of the interactions between hydrogen and transition metal catalysts is crucial for exploring novel heterogeneous hydrogenation reaction mechanisms. This study comprehensively investigates the interactions of hydrogen on active metal surfaces, revealing differences between Ni-group and Cu-group transition metals and the effects of reaction temperature and hydrogen partial pressure on stable adsorption phase diagrams. Additionally, the evolution of metal nanoparticles under moderate reaction conditions differs between Ni-group and Cu-group metals.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Xiang Xu, Xi Zhang, Andrei Ruban, Siegfried Schmauder, Blazej Grabowski
Summary: APBs are important for understanding the temperature dependence of the yield stress of Ni3Al. Accurate prediction of temperature-dependent APB energies has been lacking, and the impact of magnetism at elevated temperatures has been neglected. We show that thermally-induced magnetic spin fluctuations significantly affect the APB energies, especially for the (100)APB. Our results highlight the need to consider these spin fluctuations even for weak ferromagnetic materials like Ni3Al and the potential consequences for large-scale modeling in Ni-based superalloys.
Article
Chemistry, Physical
Mian Azmat, Abdul Majid, Mohammad Alkhedher, Sajjad Haider, Muhammad Saeed Akhtar
Summary: The prospect of using two-dimensional tetragonal samarium nitride (t-SmN) in photo-catalytic applications is being reported. First principles calculations were performed to study its structural, electronic, thermal, and photocatalytic properties. The material was found to be dynamically stable, thermally stable up to 1000 K, chemically inert at room temperature, and suitable for electrochemical reduction of water splitting. It also showed good light-harvesting ability from visible and ultraviolet regions of the solar spectrum.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Yong-Seok Choi, Hyun-Min Lee, Joo-Yeon Moon, David O. Scanlon, Jae-Chul Lee
Summary: This study presents a solution for enhancing the initial Coulombic efficiency of SnS2 anode materials in Na-ion batteries by modulating the solvation tendency of electrolyte solvents. By correlating solvent properties with first-cycle reversibility, this research offers insights for designing high-energy-density anodes based on various sodium storage mechanisms.
ENERGY STORAGE MATERIALS
(2023)
Article
Chemistry, Physical
Juan J. J. Aucar, Alejandro F. F. Maldonado, Juan I. I. Melo
Summary: In this work, relativistic corrections to the electric field gradient (EFG) are presented, including spin-dependent corrections for the first time. The results show that these new corrections significantly improve the performance of the existing method and are in close agreement with calculations at the four-component Dirac-Hartree-Fock (4c-DHF) level. The accuracy of the EFG values obtained with this new method allows for the analysis of the electronic origin of relativistic effects using well-known nonrelativistic operators.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Gabriel L. Murphy, Zhaoming Zhang, Helen E. Maynard-Casely, Joshua Stackhouse, Piotr M. Kowalski, Thomas Vogt, Evgeny Alekseev, Brendan J. Kennedy
Summary: A combined experimental and theoretical investigation was conducted to study the compressibility of two SrUO4-x polymorphs (alpha and fi) under hydrostatic conditions. The study explains the contrasting chemical and mechanical behaviors of these polymorphs by differences in oxygen defect formation chemistry. The experimental data and ab initio calculations revealed that the expansion of the uranyl bonds in alpha-SrUO4 and fi-SrUO4 under hydrostatic pressures is due to the reduction of uranium formal oxidation state and the formation of oxygen vacancies. The difference in preferred lattice sites for oxygen defect formation leads to the significant difference in apparent bulk moduli between the two polymorphs.
Article
Materials Science, Multidisciplinary
Keisuke Mukai, Ryuta Kasada, Jae-Hwan Kim, Masaru Nakamichi
Summary: In this study, first-principles calculations were performed on 42 existing binary Be intermetallics to find an effective electronic descriptor. The occupied Be p band center relative to the Fermi level was identified as a bulk descriptor, correlating with the Be vacancy formation energy. The bulk descriptor was confirmed to be an experimentally measurable scale, which can accelerate the material development of beryllium intermetallic neutron multipliers.
Article
Chemistry, Physical
Kaihua Zhang, Marco Caricato
Summary: Metal-doped amorphous silicates are promising materials for heterogeneous catalysis due to their easy preparation and tunable properties. However, the characterization of their amorphous surface is challenging, and improvements are mostly based on trial and error. This study focuses on the Nb-catalyzed epoxidation of ethylene as a test reaction to understand the factors affecting effective reaction rates. The researchers found that multiple transition state structures can exist at each site, which significantly affect the reaction barrier, and sampling of different sites is necessary.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Kaihua Zhang, Marco Caricato
Summary: Metal-doped amorphous silicates are promising materials for heterogeneous catalysis due to their easy fabrication and tunable properties. However, their amorphous surface makes characterization challenging, and improvements rely on a trial and error approach. In this study, we use the Nb-catalyzed epoxidation of ethylene as a test reaction to analyze various aspects of simulation modeling for effective reaction rate predictions. We find that each site can have multiple transition state structures with varying reaction barriers, and that sampling of multiple sites is necessary. Machine learning is employed to identify key descriptors of the active site that correlate with energy barriers.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
M. Rkhis, R. Anoua, A. Alaoui-Belghiti, S. Laasri, S. Touhtouh, E. K. Hlil, M. Bououdina, K. Zaidat, S. Obbade, A. Hajjaji
Summary: ZrNi is a promising candidate for hydrogen storage and Ni-MH rechargeable batteries. Vacancy defects, especially nickel vacancies, have a significant impact on the dehydrogenation properties of ZrNiH3. The formation enthalpy decreases with increasing vacancy concentration, affecting the stability and hydrogen storage capability of the material.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Green & Sustainable Science & Technology
Shuai Gu, Jiao Kong, Lei Xing, Xiaoran Zhu, Jun Xu, Canyu Chen, Ziyang Zhang
Summary: This study proposes an economically feasible process for regenerating Li-ion battery materials from spent portable electronics batteries. By introducing oxygen nano-bubbles, faster leaching kinetics and higher leaching capacities are achieved. The regenerated cathode material exhibits an ordered structure and excellent electrochemical performance.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Physics, Multidisciplinary
U. Friman-Gayer, C. Romig, T. Huether, K. Albe, S. Bacca, T. Beck, M. Berger, J. Birkhan, K. Hebeler, J. Hernandez, J. Isaak, S. Koenig, N. Pietralla, P. C. Ries, J. Rohrer, R. Roth, D. Savran, M. Scheck, A. Schwenk, R. Seutin, V Werner
Summary: This study reported a direct measurement of the decay width of the excited 0(1)(+) state of Li-6 using the relative self-absorption technique. The experimental value obtained provides low uncertainties for testing modern theories of nuclear forces. Additionally, the transition rate was compared to ab initio calculations based on chiral effective field theory to test the impact of two-body currents.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Jochen Rohrer, Karsten Albe
Summary: Through density functional theory calculations, the atomic structure and chemical composition of IDBs in wz ZnO bicrystals were systematically investigated, revealing that IDBs with fully coordinated atoms and relatively low excess energies are thermodynamically stable. The observed piezotronic properties of the bicrystals may not be intrinsic to the pristine GB itself, but rather originate from externally supplied charges, defects, or impurities.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Multidisciplinary Sciences
Marcel Sadowski, Karsten Albe
Summary: Ab initio molecular dynamics simulations were used to investigate the influence of low degrees of Br-/S2- site-exchange on Li+ diffusion in the argyrodite-type solid electrolyte Li6PS5Br. A new mechanism for internal Li+ reorganization was identified, with Li+ interstitials being the dominant mobile charge carriers originating from Frenkel pairs due to BrS. defects. The relative arrangement of SBr' and BrS. defects was found to be crucial for effective long-range transport of Li+.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Leonie Koch, Sebastian Steiner, An-Phuc Hoang, Arne J. Klomp, Karsten Albe, Till Froemling
Summary: Solid solutions of sodium bismuth titanate (NBT) are the most performant lead-free dielectric ceramics for energy storage. The defect chemistry of NBT is complex, and acceptor doping can result in unexpected and extraordinarily high oxygen ionic conductivity. This study elucidates the interaction between acceptors and oxygen vacancies and rationalizes the observed differences in conductivity through experiments and calculations.
Article
Physics, Applied
Lorenzo Villa, Elaheh Ghorbani, Karsten Albe
Summary: In this study, it was found through calculations that the dominant defects in antiferroelectric NaNbO3 material are Na and O vacancies, and the material is an n-type semiconductor for almost all oxygen partial pressures. Additionally, the presence of a defect complex (V-Na-V-O-V-Na) was predicted, which is stable under n- or p-type doping conditions.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Multidisciplinary Sciences
Daniel Utt, Subin Lee, Yaolong Xing, Hyejin Jeong, Alexander Stukowski, Sang Ho Oh, Gerhard Dehm, Karsten Albe
Summary: By experiments and simulations, this study investigates the reasons for dislocation pinning in high-entropy alloys. The research finds that the critical stress required for dislocation glide is proportional to the density of high local Peierls friction.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Arne J. Klomp, Ruben Khachaturyan, Theophilus Wallis, Karsten Albe, Anna Gruenebohm
Summary: This study investigates the stability of domain walls in ferroelectric material BaTiO3 using molecular dynamic simulations, and finds that microscopic thermal fluctuations play a crucial role in domain wall dynamics and stability. When domain walls are small enough, thermal fluctuations can cause the walls to come into contact and annihilate each other, thus limiting the maximum achievable domain wall density in nanoelectronic devices.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Arne J. Klomp, Lukas Porz, Karsten Albe
Summary: In this study, the nature of mechanically induced dislocations in SrTiO3 at low temperatures is investigated. The results reveal the importance of the splitting into partial dislocations for the dislocation mobility in strontium titanate.
Article
Chemistry, Physical
Marcel Sadowski, Leonie Koch, Karsten Albe, Sabrina Sicolo
Summary: In this study, the chemomechanical properties of LiCoO2 and LiNiO2 were compared by combining density functional theory and anisotropic linear elasticity theory. The study found that excess Ni hinders stacking-sequence changes and Jahn-Teller distortions affect the compliance behavior of LiNiO2. Additionally, vacancies tend to segregate along dislocation lines.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Edina Sic, Jochen Rohrer, Emmanuel Ricohermoso, Karsten Albe, Emmanuel Ionescu, Ralf Riedel, Hergen Breitzke, Torsten Gutmann, Gerd Buntkowsky
Summary: Polymer-derived silicon oxycarbide ceramics (SiCO) have been investigated as potential anode materials for lithium- and sodium-ion batteries. This study focuses on understanding the local structures of SiCO ceramics with different amounts of carbon. Through various spectroscopic and computational techniques, significant changes in the local structures of SiCO ceramics have been observed, even with small changes in the material composition. These findings will provide valuable insights into the electrochemical storage processes of alkali metal/ions inside polymer-derived ceramics, particularly in the context of future research.
Article
Chemistry, Physical
Yangyiwei Yang, Timileyin David Oyedeji, Xiandong Zhou, Karsten Albe, Bai-Xiang Xu
Summary: Designing the microstructure of Fe-Ni permalloy produced by additive manufacturing (AM) allows for customizing its magnetic properties. However, AM-produced parts exhibit spatially inhomogeneous thermal-mechanical and magnetic responses, which have been less studied in terms of process modeling and simulations. In this study, we propose a powder-resolved multiphysics-multiscale simulation scheme that explicitly considers the coupled thermal-structural evolution with associated thermo-elasto-plastic behaviors and chemical order-disorder transitions. By employing this scheme, we investigate the dependence of fusion zone size, residual stress and plastic strain, and magnetic hysteresis on beam power and scan speed for AM-produced Fe21.5Ni78.5. Results also demonstrate a phenomenological relation between magnetic coercivity and average residual stress, providing guidance for the design of magnetic hysteresis in soft magnetic materials through appropriate processing parameters.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Energy & Fuels
Elaheh Ghorbani, Martin Schiller, Hans H. Falk, Leonard A. Waegele, Stefanie Eckner, Francesco d'Acapito, Roland Scheer, Karsten Albe, Claudia S. Schnohr
Summary: In this study, the incorporation site and electronic structure of vanadium-doped indium sulfide thin films were investigated. Experimental results showed that vanadium occupies octahedral coordinated indium sites instead of tetrahedral. Additionally, at low concentrations, octahedrally coordinated vanadium forms an isolated intermediate band, which alters the band structure of the material.
JOURNAL OF PHYSICS-ENERGY
(2023)
Article
Chemistry, Physical
Vasiliki Faka, Matthias T. Agne, Paul Till, Tim Bernges, Marcel Sadowski, Ajay Gautam, Karsten Albe, Wolfgang G. Zeier
Summary: Understanding the transport in Li+ solid ionic conductors is crucial for solid-state battery development. The influence of activation volumes on ion transport in solid electrolytes has gained attention. This study determined the activation volumes for Li+ migration in Li6PS5Br materials and found that they increase with higher degrees of Br-/S2- site disorder and more spatially distributed lithium-ions.
Article
Materials Science, Multidisciplinary
Lorenzo Villa, Karsten Albe
Summary: The influence of doping on defect equilibrium and double P-E loops in NaNbO3 material was studied. Formation energies, charge transition levels, and doping behavior of single defects and defect complexes doped with Ca, Sn, and Sr in orthorhombic NaNbO3 were calculated using density functional theory (DFT). The results show that dopants substitutions have low formation energies and all defect complexes have negative binding energy.
Article
Chemistry, Physical
Markus Mock, Matteo Bianchini, Francois Fauth, Karsten Albe, Sabrina Sicolo
Summary: Through operando X-ray diffraction and Monte Carlo simulations, combined with Density Functional Theory, discrepancies between experiments and theory in the LiNiO2 phase diagram have been successfully resolved. Off-stoichiometry and elemental substitution play a crucial role in disrupting Li ordering, suppressing phase transitions, and promoting solid-solution behavior and smooth discharge curves.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Chemistry, Physical
Erhao Gao, Wenjing Feng, Qi Jin, Li Han, Yi He
Summary: The influence of K-doping on the reactive oxygen species and elementary reactions of HCHO catalytic oxidation was investigated using density functional theory (DFT). The introduction of K-doping changed the electronic structures of Ce and O, facilitating the adsorption and activation of HCHO and O2 molecules, enhancing lattice oxygen mobility, and reducing the energy barrier for HCHO oxidation. K-doping also promoted the formation of hydroxyl groups, facilitating HCHO adsorption and oxidation.
Article
Chemistry, Physical
Hao Fu, Zhangliang Xu
Summary: In this study, the adsorption mechanisms and detection performance of formaldehyde, ammonia, and sulfur dioxide on undoped and metal-doped ZnO surfaces were investigated using density functional theory. The results showed that formaldehyde and ammonia were physically adsorbed on the undoped ZnO surface, while sulfur dioxide was weakly chemisorbed. The adsorption energy was enhanced when ZnO was doped with metals. These findings provide theoretical guidance for the application of ZnO substrate materials in gas sensitivity research.
Article
Chemistry, Physical
Atsushi Nomura, Tohru Kurosawa, Migaku Oda, Satoshi Demura, Shogo Kuwahara, Sora Kobayashi, Hideaki Sakata
Summary: The study investigates the tunneling spectra of 1T-TiSe2 in the CDW state and the dip structure below the Fermi level, aiming to determine whether this dip is a CDW gap. The answer to this question is crucial for understanding the driving mechanism of CDW.
Article
Chemistry, Physical
A. S. Petrov, D. I. Rogilo, A. I. Vergules, V. G. Mansurov, D. V. Sheglov, A. V. Latyshev
Summary: This study investigates Si mass transport and morphological transformations on the Si(111) surface during (root 3 x root 3)-Sn reconstruction formation and Si homoepitaxy. The research shows that the formation of different Sn phases at different temperatures affects the Si island nucleation and monatomic step shift, which in turn impact the morphology of the Sn/Si(111) interface. Electromigration-induced drift of disordered Sn domains leads to enhanced noncompensated Si mass transport and surface roughening.
Article
Chemistry, Physical
D. V. Gruznev, L. V. Bondarenko, A. Y. Tupchaya, A. A. Yakovlev, A. N. Mihalyuk, A. V. Zotov, A. A. Saranin
Summary: Deposition of thallium (Tl) onto the Au/Si(111)5 x 2 reconstruction followed by annealing results in the formation of a surface structure with 4 x 2 periodicity. The immiscibility of Au and Tl leads to the migration of Tl atoms over the Si chains. Thallium donates electrons to the surface, converting the metallic surface into an insulating state and altering the inter-chain distance within the array of Au atomic wires.
Article
Chemistry, Physical
Simone Giusepponi, Francesco Buonocore, Barbara Ferrucci, Massimo Celino
Summary: Using ab-initio calculations, the interaction between lead adatom and both clean and doped iron (100) surfaces was investigated. It was found that the lead adatom prefers to adsorb in the hollow site, which is more stable compared to the top and bridge sites, and in this position, it is energetically favorable over the iron adatom. Moreover, lead adsorbed in the hollow site of the iron (100) surface doped with chromium was found to create a more stable system compared to nickel-doped surfaces with an iron adatom in the same position. The study also explored inter-layer distances, bonding mechanisms, magnetic behaviors, and charge density differences. The results provide insights into the role of doping in the interaction between lead adatom and iron surface, and have implications for the analysis of corrosion processes caused by liquid lead.
Article
Chemistry, Physical
Shuo Zhang, Jin-Ho Choi
Summary: The recent synthesis of two-dimensional layered WSi2N4 has attracted attention due to its potential applications. This study investigates the catalytic performance of WSi2N4 monolayers with nitrogen vacancies in the hydrogen evolution reaction using first-principles calculations. The results show that the defective WSi2N4 monolayers exhibit remarkably high catalytic activity comparable to platinum catalysts. Electronic structure calculations also reveal the emergence of spin-polarized states due to the introduction of nitrogen vacancies.
Article
Chemistry, Physical
Xiaoyan Yu, Xin Cao, Wei Kang, Shanhua Chen, Ao Jiang, Yuhao Luo, Wenwei Deng
Summary: First-principles calculations were used to investigate the electronic properties of a TiO2 heterostructure modified with Bi2Te3 co-catalyst. The study revealed that the Bi2Te3/TiO2 interface introduced optimal band offsets, effectively suppressing electron-hole recombination and enhancing the utilization efficiency of photo-generated carriers. Additionally, the Bi2Te3 co-catalyst introduced extra catalytic active sites, further boosting the photo-catalytic hydrogen evolution efficiency.
Article
Chemistry, Physical
Filippo Longo, Emanuel Billeter, Selim Kazaz, Alessia Cesarini, Marin Nikolic, Aarati Chacko, Patrik Schmutz, Zbynek Novotny, Andreas Borgschulte
Summary: Alkaline water electrolysis is a simple and efficient method for renewable hydrogen production, utilizing cheap and abundant transition metals. The catalytic properties of Ni materials are enhanced by the formation of oxidized compounds on the surface. The high electrocatalytic activity of Ni (oxy)-hydroxides is directly related to water intercalation in the passivation layer, supporting the hypothesis of a water mediated OH- diffusion mechanism. The self-organization of the surface structure during passivation layer formation enables high electrode performance.
Article
Chemistry, Physical
Mohan Kumar Kuntumalla, Miriam Fischer, Alon Hoffman
Summary: By investigating the bonding, retention, and thermal stability of nitrogen in H-Diamond (100), it was found that nitrogen can partially recover its bonding with carbon atoms after high-temperature annealing, indicating a high thermal stability of nitrogen in diamond.
Article
Chemistry, Physical
Dong Yue, Liangying Wen, Rong Chen, Jianxin Wang, Zhongqing Yang
Summary: The adsorption behavior of Cl2 molecules on the TiC surface and the formation and transfer of reaction products were studied using first-principles ab initio calculations. The results show that the Cl atoms bonded to the surface Ti atoms are more stable, and the TiCl3 intermediate is easier to form than the TiCl2 intermediate.
Article
Chemistry, Physical
Yatao Wang, Peng Zhang, Hongjuan Li, Qiuju Xu, Shujun Liu, Xiaopeng Liu, Xuehua Guo, Yitao Li, Jinzhang Liu, Sen Dong, Zhi Wei Seh, Qianfan Zhang
Summary: In this study, the adsorption performance of two types of metal-organic frameworks (MOFs) for thiophene and benzene was experimentally investigated. The results showed that IZE-1 exhibited high selectivity and superior adsorption capacity for thiophene, especially at low concentrations. First-principles calculations and molecular dynamics simulations provided insights into the mechanism of thiophene adsorption and the high selectivity observed. This research demonstrates the potential of MOFs for thiophene adsorption, particularly at high concentrations.
