Article
Chemistry, Multidisciplinary
Alexander S. Frolov, Carolien Callaert, Maria Batuk, Joke Hadermann, Andrey A. Volykhov, Anna P. Sirotina, Matteo Amati, Luca Gregoratti, Lada Yashina
Summary: This study investigates the reaction between the GeTe (111) surface with molecular oxygen, focusing on crystals with sole inversion domains. The reaction kinetics and structure of the oxide layer are evaluated, revealing nanoscale phase separation of GeO2 and Te, which is unusual for semiconductors.
Article
Chemistry, Multidisciplinary
Oskar Cheong, Thomas Bornhake, Xinwei Zhu, Michael H. Eikerling
Summary: A computational study was conducted to investigate the impact of solvation on the reduction reaction of CO2 to formic acid and carbon monoxide on Pb(100) and Ag(100) surfaces. The results provide insights into how solvation affects the adsorption energies of reaction intermediates. By applying an explicit solvation scheme using a combined DFT/microkinetic modeling approach, the study reveals the selectivity for CO formation on Ag and HCOOH formation on Pb, resolving the discrepancy between theoretical calculations and experimental observations. The detailed analysis of adsorption energies highlights the significance of the total number of hydrogen bonds formed by HCOO in determining the adsorption strength of intermediates and the electrocatalytic activity. The findings underscore the importance of explicit solvation for understanding adsorption and electrochemical reaction phenomena on metal surfaces.
Article
Chemistry, Physical
Tatsuya Ishiyama
Summary: NE-AIMD simulations were used to study the vibrational energy relaxation path of excited non-hydrogen-bonded OH at an air/water interface. The simulations reproduced experimentally observed features, showing that relaxation time scales of free OH at the surface of pure water and isotopically diluted water are similar. It was found that both stretching vibrational coupling and bend-stretching combination band contribute to the relaxation path of free OH at the surface.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Jiguang Du, Gang Jiang
Summary: The Ca2B8 cluster is predicted to be a stable symmetrical 3-dimension complex with aromaticity, showing potential as a hydrogen storage material with high adsorption energy and gravimetric density. The charge analysis and molecular orbital studies reveal the mechanism of formation and release of the adsorbed H2 molecules on Ca2B8.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Yulun Han, Kweeni Iduoku, Gena Grant, Bakhtiyor Rasulev, Alexey Leontyev, Erik K. Hobbie, Sergei Tretiak, Svetlana Kilina, Dmitri S. Kilin
Summary: This study investigates the thermal grafting of benzenediazonium bromide onto a hydrogenated Si(111) surface and its impact on photophysics of charge carriers. Results show that coverage of phenyl groups can reduce nonradiative relaxation rates and recombination rates of hot charge carriers, leading to increased photoluminescence efficiency in the near-infrared spectral region.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(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
Chemistry, Physical
Zuxin Jin, Joseph E. Subotnik
Summary: A new scheme is proposed for modeling molecular nonadiabatic dynamics near metal surfaces, utilizing the charge-transfer character of such dynamics. This scheme allows the construction of an efficient reduced representation for the electronic structure, and modification of the FSSH approach to include electronic relaxation. The resulting FSSH-ER method is validated across a wide range of coupling strengths, with plans to integrate it with ab initio electronic structure calculations in future work.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Multidisciplinary
Krzesimir Korona, Michal Terlecki, Iwona Justyniak, Michal Magott, Jan Zukrowski, Arkadiusz Kornowicz, Dawid Pinkowicz, Adam Kubas, Janusz Lewinski
Summary: Paddlewheel-type binuclear complexes with metal-metal bonding have attracted widespread interest due to their electronic structures and potential applications. In this study, the molecular and electronic structures of diiron(II,II) complexes with different ligands were explored, providing insight into the factors controlling their ground-state electronic configuration and structural diversity.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Physics, Applied
Dangqi Fang
Summary: The study found that electron-phonon coupling leads to a reduction in the indirect bandgap of MgSiN2, with calculated bandgap showing good agreement with experimental results when considering bandgap renormalization. Additionally, the predicted phonon-assisted optical absorption spectra show a redshift in absorption onset with increasing temperature.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Biao Yu, Yanfeng Han, Dong Li, Guangmin Hu, Qing Dong, Jiao Zhang, Baode Sun
Summary: The structures, surface energies, and electronic properties of Ti2AlN(0001) surfaces were studied at temperatures ranging from 0 K to 1273 K using ab initio molecular dynamics and first-principles calculations. It was observed that the structural relaxations of Ti(N)- and Ti(Al)-terminated surfaces mainly occurred between the outermost two layers, while those of N(Ti)- and Al(Ti)-terminated surfaces extended into the third layer. The N(Ti)-terminated surface exhibited the largest relaxation, while the Al(Ti)-terminated surface was the most stable at all temperatures. The thermal expansion of the d-spacing of Al-Ti layers affected the relaxation of the outermost two layers for Al(Ti)and Ti(Al)-terminated surfaces. The redistribution of Ti-3d, N-2p, and Al-3p orbitals influenced the electronic properties and structural relaxations of different termination surfaces at all temperature ranges.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Kohei Tada, Hiroyuki Ozaki, Koji Fujimaru, Yasutaka Kitagawa, Takashi Kawakami, Mitsutaka Okumura
Summary: The study found that surface interactions can tune chemical indices and that weak adsorption onto ionic solids with charge-dipole interactions can enhance diradical character.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Min He, Chidozie Onwudinanti, Yaoting Zheng, Xiaomei Wu, Zaoxiao Zhang, Shuxia Tao
Summary: This study utilized Density Functional Theory (DFT) to analyze the stability of chromium, molybdenum, and vanadium carbides in 2.25Cr1Mo0.25V steel, as well as their corresponding hydrides. The results showed that V6C5 is the most stable carbide in its metal-carbon binary system and exhibits the strongest hydrogen absorption ability.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Sobia Younas, Aqdas Riaz, Haq Nawaz, Muhammad Irfan Majeed, Muhammad Adnan Iqbal, Nosheen Rashid, Areeba Altaf, Umar Sohail Shoukat, Faisal Jamil, Aafia Sehar, Sania Munir, Mahrosh Javed, Muhammad Imran
Summary: In this study, Raman spectroscopy along with density functional theory (DFT) calculations were used to characterize and confirm the formation of three different selenium-based N-heterocyclic carbene (NHC) complexes. The analysis of mean RS features and DFT calculations showed that the polarizability of benzimidazolium rings increased after complex formation with selenium, indicating the formation of newly formed bonds. The identification of new peaks in the spectra of the complexes further confirmed their formation. Principal Component Analysis (PCA) was used to analyze the Raman spectral data sets, demonstrating the efficiency of RS analysis. Overall, the results demonstrated the fast and effective use of RS and DFT for confirming the synthesis of selenium-based NHC complexes.
Article
Chemistry, Physical
T. Kana, J. Cermak, L. Kral
Summary: Ab initio calculations were performed on Mg2Ni compound and its hydride Mg2NiH4 doped with elements X = Al, Ga, In, Si, Ge, and Sn, showing a reduction in hydrogen desorption enthalpy for both concentrations of X. Doping with In at low concentration weakened Ni-H bonds in Mg-2(Ni-In)H-4 hydride while enhancing bonding between Mg and H atoms. These findings provide valuable insights into enhancing hydrogen storage properties in metal hydride systems.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Ryan Gotchy Mullen, Nir Goldman
Summary: Hydriding corrosion of plutonium causes surface cracking, pitting, and structural failure. This study calculates the surface energies of low facet surfaces of face-centered cubic delta-Pu, and discusses the adsorption free energies of hydrogen structures at different coverage levels, as well as the progression of filling sites with increasing H-2 partial pressure. Implications for near-equilibrium pressure hydride nucleation and non-equilibrium millibar pressure hydriding are explored.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Yong Li, Bao-Nam Ngo-Dinh, Juergen Markmann, Joerg Weissmueller
Summary: The study explores the evolution of silver-rich clusters in nanoporous gold formation through dealloying, illustrating their impact on the material's functional behavior. The size of these clusters decreases with increasing dealloying potential, showing a similar trend to that of ligaments. Experimental simulations confirm that the size of the silver-rich clusters can be measured and provides an experimental signature of the initial size in the process.
Article
Materials Science, Multidisciplinary
C. Haug, D. Molodov, P. Gumbsch, C. Greiner
Summary: Tribological loading induces microstructural changes in metals through dislocation-mediated plastic deformation. Crystal lattice rotations play an important role in friction and wear at the sliding interface, and are influenced by sliding direction and grain orientation.
Article
Materials Science, Multidisciplinary
Joerg Weissmueller, Shan Shi
Summary: Elastic compliance of porous metals can be greatly enhanced by alloying mobile solutes into interstitial sites of the crystal lattice, as recent experiments have shown. These observations support the predictions by Gorsky and Larche and Cahn for the elasticity of open systems probed at constant chemical potential. The mechanism behind this enhancement involves an exchange of solutes between tensile and compressive fibers in the microstructure's beam-like elements.
Article
Engineering, Chemical
Hannes Holey, Andrea Codrignani, Peter Gumbsch, Lars Pastewka
Summary: The cornerstone of thin-film flow modeling is the Reynolds equation, but its derivation is based on specific assumptions about the fluid constitutive behavior, limiting its applicability in multiscale scenarios. In this study, a method is introduced to treat the macroscopic flow evolution and local cross-film stresses as separate yet coupled problems, overcoming this limitation and validating the approach using examples.
Article
Chemistry, Physical
Alex Ricardo Silva Olaya, Franziska Kuehling, Christoph Mahr, Birthe Zandersons, Andreas Rosenauer, Joerg Weissmueller, Gunther Wittstock
Summary: Nanoporous gold (NPG) with less than 1% residual Ag content was studied as an electrocatalyst for the oxidation of methanol, formaldehyde, and formate. The surface structure and oxidation reaction of NPG can be controlled by adjusting the Ag content and potential. Ag has a significant impact on the onset potential and peak current density of the catalytic reaction.
Article
Engineering, Mechanical
Ali Riza Durmaz, Erik Natkowski, Nikolai Arnaudov, Petra Sonnweber-Ribic, Stefan Weihe, Sebastian Munstermann, Chris Eberl, Peter Gumbsch
Summary: This study proposes a validation framework where a fatigue test is simulated by embedding measured microstructures into the specimen geometry and adopting an approximation of the experimental boundary conditions. A phenomenological crystal plasticity model is applied to predict deformation in ferritic steel, and the hotspots in commonly used fatigue indicator parameter maps are compared with damage segmented from micrographs. The framework is published for benchmarking future micromechanical fatigue models.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Chemistry, Multidisciplinary
Gideon Henkelmann, Diana Waldow, Maowen Liu, Lukas Luehrs, Yong Li, Joerg Weissmueller
Summary: Experimental results show that thin films of dealloyed nanoporous gold (NPG) spontaneously detach from massive gold base layers and densify near the external surface. This behavior is reproduced by kinetic Monte Carlo (KMC) simulation and is common for nanoscale network materials evolving by surface diffusion.
Article
Chemistry, Physical
Xin Fang, Jihong Wen, Li Cheng, Dianlong Yu, Hongjia Zhang, Peter Gumbsch
Summary: This research demonstrates a design paradigm for creating robust robotic metamaterials using versatile gear clusters. The design allows for continuous tuning of elastic properties while maintaining stability and robust maneuverability, even under heavy loads. The gear-based metamaterials offer excellent properties such as tunable Young's modulus, shape morphing, and fast response.
Article
Multidisciplinary Sciences
Nikolay T. Garabedian, Paul J. Schreiber, Nico Brandt, Philipp Zschumme, Ines L. Blatter, Antje Dollmann, Christian Haug, Daniel Kuemmel, Yulong Li, Franziska Meyer, Carina E. Morstein, Julia S. Rau, Manfred Weber, Johannes Schneider, Peter Gumbsch, Michael Selzer, Christian Greiner
Summary: This paper discusses the lack of FAIR (Findable, Accessible, Interoperable, and Reusable) data and metadata in experimental tribology and proposes a scalable framework for generating FAIR data. Through collaboration with developers, crowdsourcing controlled vocabulary, ontology building, and the use of digital tools, this paper demonstrates a collection of scalable non-intrusive techniques to improve the lifespan, reliability, and reusability of experimental tribological data.
Article
Chemistry, Multidisciplinary
Navid Hussain, Torsten Scherer, Chittaranjan Das, Janis Heuer, Rafaela Debastiani, Peter Gumbsch, Jasmin Aghassi-Hagmann, Michael Hirtz
Summary: This study explores the interaction between capillary-printed Galinstan and gold surfaces, revealing the spreading process of liquid metals on gold films and the formation of intermetallic nanostructures. By utilizing various microscopy techniques, a comprehensive understanding of the material interaction between LM and gold is achieved.
Article
Materials Science, Multidisciplinary
Maowen Liu, Joerg Weissmueller
Summary: This study investigates the microstructure and phase decomposition in nanoporous Au-Pt materials fabricated by dealloying. The findings reveal that the enrichment of Pt at the surface and Pt depletion in the bulk during dealloying result in a homogeneous single-phase state in the material. Annealing induces diffusion-driven coarsening and the formation of Pt-rich regions with crystallographic coherence and semi-coherent regions. The study demonstrates the high kinetic stability and tunability of surface composition in nanoporous alloys through annealing.
Article
Materials Science, Multidisciplinary
Kolja Zoller, Patric Gruber, Michael Ziemann, Alexander Goertz, Peter Gumbsch, Katrin Schulz
Summary: Microwires have gained increasing interest for miniaturizing structural components. Understanding the deformation behavior of microwires is crucial for assessing their applicability and lifespan in specific components. This study analyzes the microstructure evolution of single crystalline gold microwires under torsion, specifically for high-symmetry crystal orientations (100), (110), and (111), using simulation and experimental results. The classification of slip systems can be predicted through theoretical considerations, and it is found that slip system activity, stress relaxation mechanism, and dislocation density depend on specific slip system groups.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Kai Xia, Zheqin Dong, Qing Sun, Rafaela Debastiani, Sida Liu, Qihao Jin, Yang Li, Ulrich W. Paetzold, Peter Gumbsch, Uli Lemmer, Yolita M. Eggeler, Pavel A. Levkin, Gerardo Hernandez-Sosa
Summary: 3D-printed conductive structures with customized properties are fabricated using digital light processing technology and inkjet printing. By optimizing the deposition conditions, conductive structures with sheet resistance <2 ohm sq(-1) are achieved. The integration of an inkjet-printed photodetector onto the nanoporous substrate demonstrates the potential for additive manufacturing of functional 3D-printed optoelectronic devices.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Sambit Bapari, Lukas Luehrs, Joerg Weissmueller
Summary: Researchers use nanoporous gold (NPG) and a leveled-wave model to characterize the characteristic length scale of random bicontinuous microstructures. By comparing experiment and model, they find that the size distribution is uniform over the cross-section of NPG samples and evolves self-similarly upon coarsening. The electrochemical capacitance ratio method accurately measures the size and correlates well with the model. The findings provide conversion factors between different size metrics and demonstrate the combination of NPG and the leveled-wave model as a showcase for characterizing random microstructures.
Article
Physics, Multidisciplinary
Hannes Holey, Peter Gumbsch, Lars Pastewka
Summary: This study employs molecular dynamics simulations to investigate flow at the molecular scale and explores the influence of in-plane wavelengths. By probing the long wavelength limit in thermodynamic equilibrium, anomalous relaxation of density and longitudinal momentum fluctuations is observed, which can be described by an effective continuum theory.
PHYSICAL REVIEW LETTERS
(2023)
