Article
Physics, Applied
Emily M. Turner, Quinn Campbell, Ibrahim Avci, William J. Weber, Ping Lu, George T. Wang, Kevin S. Jones
Summary: The selective amorphization of SiGe in Si/SiGe nanostructures was achieved through ion implantation. SiGe fins and pillars encapsulated Si nanowires and quantum dots, respectively, during high-temperature dry oxidation. Interestingly, different sizes of Si QDs and Si NWs exhibited different crystalline stability during ion implantation. Monte Carlo simulations showed similar displacement levels, while molecular dynamics simulations suggested that the difference in total stress magnitude may lead to crystalline instability in QDs. This finding is of special importance for applications requiring robust QD devices in radiation environments.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Hadi Rezaie Heris, Movaffaq Kateb, Sigurdur I. Erlingsson, Andrei Manolescu
Summary: In this study, the effects of geometry on the thermal conductivity of silicon and germanium nanowires were investigated using molecular dynamics simulations. The length, diameter, and transverse geometry of the nanowires were considered. Heat transport in tubular nanowires and core/shell structures of Si/Ge and Ge/Si were compared to the heat transport in the separated core and shell components.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Physical
Hisashi Matsuyama, Kota Motoyoshi
Summary: The empirical equation relating limiting ionic molar conductivity (lambda(infinity)) to self-diffusion coefficient (D) in water and methanol was investigated in an acetonitrile solution, showing excellent agreement with experimental data. Molecular dynamics simulations successfully obtained self-diffusion coefficients at different temperatures, demonstrating the value of combining this method with simulations for calculating D and s.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Hongquan Lu, Bin Dong, Junqian Zhang, Chaofeng Lu, Haifei Zhan
Summary: This study investigated the deformation behavior of copper nanowire under coupled tension-torsion loading using atomistic simulations. The results showed that the yielding pattern and dislocation pattern of the nanowire varied with different torsion/tension strain ratios. Additionally, the deformation behavior of the nanowire differed under tension-dominated loading and torsion-dominated loading. These findings have important implications for engineering applications.
Article
Crystallography
Dandan Zhao, Yang Cui, Jing Li, Lin Zhang
Summary: Molecular dynamics simulations were used to study the structural and mechanical properties of Si/Ge core-shell nanowires at different temperatures. The results showed that temperature and strain have a significant effect on the performance of these nanowires, and the core-shell ratio affects the Young's modulus.
Article
Mechanics
Dongyuan Du, Chao Tang, Yujing Tang, Lu Yang, Jian Hao
Summary: This study used molecular dynamics simulation technology to investigate the impact of carbon nanowires on the thermodynamic properties of cellulose insulating paper. The results showed that different structures of carbon nanowires can improve the thermodynamic properties of cellulose, with hard chiral carbon nanowires having the most significant effect.
COMPOSITE STRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Dandan Zhao, Feng Dai, Jing Li, Lin Zhang
Summary: Molecular dynamics simulations were used to investigate the packing changes and mechanical properties of tilted interface Si/Ge superlattice nanowires. The results show that the size, layer thickness, and interface bonding have significant effects on the thermal stability and mechanical properties of the nanowires.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Ceramics
Chen-yang Ran, Li-li Zhou, Yong-chao Liang, Yun-fei Mo, Qian Chen, Ze-an Tian, Rang-su Liu, Ting-hong Gao, Quan Xie
Summary: A molecular dynamics simulation was conducted to investigate Si-like and TCP structures in AuxSi(100_ x) alloys during rapid solidification, revealing the formation of Si-like structures in Si-rich alloys and TCP structures in Au-rich alloys. The study provides new insights for analyzing amorphous structures between transition metals and semiconductors.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Nanoscience & Nanotechnology
Chappel S. Thornton, Blair Tuttle, Emily Turner, Mark E. Law, Sokrates T. Pantelides, George T. Wang, Kevin S. Jones
Summary: A new Ge diffusion mechanism has been discovered that enables the formation of single-crystal Si nanowires and quantum dots in a defect-free, single-crystal SiGe matrix along the oxidizing interface of Si/SiGe nanostructures. The oxidation studies of Si/SiGe nanofins were conducted to understand this novel mechanism better. It was found that the activation energy for Ge diffusion along the sidewall is much lower than that for Ge diffusion in bulk Si, indicating a different diffusion behavior.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Chappel S. Thornton, Blair Tuttle, Emily Turner, Mark E. Law, Sokrates T. Pantelides, George T. Wang, Kevin S. Jones
Summary: Oxidation studies of Si/SiGe nanofins have shown that the diffusion rate of Ge along the Si/SiO2 interface is faster than in bulk Si. This finding suggests that the redistribution of Ge occurs through diffusion along the Si/SiO2 interface followed by reintroduction into substitutional positions in the crystalline Si.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Xiguang Li, Chunya Wu, Bo Hou, Jiahao Wu, Ruijiang Sun, Mingjun Chen
Summary: In this study, the interface behaviors between polydopamine (PDA) and graphene oxide (GO) were investigated using classical molecular dynamics simulations. The results showed that the increase in PDA oxidation degree enhanced the adsorption capacity of GO to PDA, due to the resonance effect of substituents on the polarity of functional groups. The study also revealed the crucial role of inter-/intramolecular hydrogen bonds in mediating the adsorption of PDA, with non-amine-participating hydrogen bonds promoting PDA adsorption and amine-participating hydrogen bonds having limited benefits.
APPLIED SURFACE SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Dandan Zhao, Yue Guan, Zhennan Wu, Lin Zhang
Summary: Atomic modeling and machine learning were used to predict the thermal ability, mechanical properties, and Young's modulus of Si hollow nanowires. The study found that the cross-sectional size of the nanowires significantly affects their Young's modulus, and certain temperature or applied strain ranges can lead to transitions from hollow nanostructures to solid nanowires. Insights into the loading states of the atoms during tension were provided through the distribution of Lode-Nadai values in the nanowires.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Multidisciplinary
Gui-ping Zhu, Chang-wei Zhao, Xi-wen Wang, Jian Wang
Summary: Phonon scattering from internal body defects has a stronger impact on thermal conductivity in Si-NWs than that from surface structures in the low-porosity range. Thermal conductivity shows an exponential decay with porosity in the low-porosity range. Si-NWs with higher porosity approach the amorphous limit in thermal conductivity and are insensitive to specific phonon scattering processes.
CHINESE PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Lin Guo, Wenqing Shen, Kumar Satish, Zhigang Liu, Guihua Tang
Summary: This study proposes a bionic lubricant-impregnated surface structure that can efficiently detach sticky Wenzel condensates. Molecular dynamics simulations are used to investigate the dynamic behavior of droplets, and it is found that the proposed surface enables spontaneous movement of droplets trapped in the Wenzel state. Furthermore, the surface allows control over nucleation sites and reduces nucleation energy barriers.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Wei Shang, Fang Wu, Shiquan Jiang, Yuqing Wen, Ning Peng, Jiqiong Jiang
Summary: A three-layer composite coating was prepared on the surface of a magnesium alloy using microarc oxidation and self-assembly technology. The hydrophilicity of the self-assembled layer affected the morphological defects and thickness of the composite coating, thereby influencing the corrosion resistance.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Zhaolun Cui, Shengyan Meng, Yanhui Yi, Amin Jafarzadeh, Shangkun Li, Erik Cornelis Neyts, Yanpeng Hao, Licheng Li, Xiaoxing Zhang, Xinkui Wang, Annemie Bogaerts
Summary: Plasma-catalytic CO2 hydrogenation for methanol production was studied using a combination of experimental and computational methods. Results showed a synergistic effect between the Cu/gamma-Al2O3 catalyst and CO2/H2 plasma, with enhanced methanol selectivity achieved through the addition of H2O. Computational calculations revealed the bifunctional effect of Cu-13/gamma-Al2O3 interface sites in activating CO2 molecules and promoting hydrogenation of key intermediates. This study provides new insights into the mechanism of CO2 hydrogenation through plasma catalysis, and offers inspiration for the conversion of other small molecules using supported-metal clusters.
Article
Chemistry, Physical
C. Pashartis, M. J. van Setten, M. Houssa, G. Pourtois
Summary: The critical dimensions of electronic device patterns have been reduced to a few nanometers due to miniaturization. At this scale, the mechanical integrity of thin films deviates from their bulk material values, causing reliability issues. Understanding these fundamental aspects is crucial for technology advancements.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Sergiu Clima, Anne S. Verhulst, Pratik Bagul, Brecht Truijen, Sean R. C. McMitchell, Ingrid De Wolf, Geoffrey Pourtois, Jan Van Houdt
Summary: In this study, an analytical model and first-principles simulations were used to investigate the impact of electric dipole switching on the dielectric response of ferroelectric materials. It was found that the dielectric response undergoes nonconstant changes with applied electric field due to changes in potential energy near the switching point. These findings play an important role in the prediction of capacitance-voltage characteristics of metal-ferroelectric-metal capacitors.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Physical
Laura Galleni, Faegheh S. Sajjadian, Thierry Conard, Daniel Escudero, Geoffrey Pourtois, Michiel J. van Setten
Summary: We propose a simple additive approach to simulate X-ray photoelectron spectra (XPS) of macromolecules based on the GW method. Instead of using the computationally expensive G(0)W(0) method, we break down the macromolecule into smaller building blocks and calculate the theoretical spectra of each component. By summing up the spectra of each component with their molar ratio, we achieve excellent agreement with experimental data. This method has the potential to retrieve the composition of unknown materials and study chemical reactions.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Physics, Applied
Maksudbek Yusupov, Debbie Dewaele, Pankaj Attri, Umedjon Khalilov, Frank Sobott, Annemie Bogaerts
Summary: This study unravels the possible mechanisms of oligosaccharide oxidation induced by cold atmospheric plasma (CAP), providing atomic-level insight into the onset of plasma-induced removal of biofilms.
PLASMA PROCESSES AND POLYMERS
(2023)
Article
Chemistry, Physical
Kristof M. Bal, Erik C. Neyts
Summary: We calculate bubble nucleation rates in a Lennard-Jones fluid using molecular dynamics simulations and validate common modeling techniques. The results show consistent rate predictions from different methods, except for the rates derived from forward flux sampling simulations, which are outliers.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Z. Javdani, N. Hassani, F. Faraji, R. Zhou, C. Sun, B. Radha, E. Neyts, F. M. Peeters, M. Neek-Amal
Summary: The recent advances in the fabrication of artificial nanochannels have allowed for new research on the transport, permeance, and selectivity of various gases and molecules. However, the presence of unwanted molecules such as hydrocarbons can contaminate and clog the nanochannels, affecting their functionality.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Medicinal
Esteban Marques, Stefan de Gendt, Geoffrey Pourtois, Michiel J. van Setten
Summary: Machine learning can be used to predict chemical activation energies, improving accuracy and reducing computational cost.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Biochemistry & Molecular Biology
Esteban A. A. Marques, Stefan De Gendt, Geoffrey Pourtois, Michiel J. J. van Setten
Summary: The availability of thermochemical properties is important for predicting the equilibrium compositions of chemical reactions. Thermochemistry calculated from first-principles methods like DFT can be used for new processes. In this study, 117 molecules were used to construct 2648 reactions and benchmarked against DFT for different functionals and basis sets. The results show that DFT can accurately predict equilibrium compositions without temperature dependence below 1000 K and demonstrate correct qualitative behavior for temperature-dependent compositions.
Article
Chemistry, Physical
U. Khalilov, M. Yusupov, G. B. Eshonqulov, E. C. Neyts, G. R. Berdiyorov
Article
Physics, Applied
Kamoliddin Mehmonov, Aziza Ergasheva, Maksudbek Yusupov, Umedjon Khalilov
Summary: The unique physical properties of carbyne, a novel carbon nanostructure, have attracted significant attention in nanotechnology. In this simulation-based study, the mechanisms of endohedral carbyne synthesis from carbon and carbon monoxide radicals with a nickel catalyst were investigated. The results revealed that the introduction of carbon atoms promoted the formation of elongated carbon chains, while the presence of carbon monoxide radicals inhibited the growth of carbyne chains.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Fahim Faraji, Mehdi Neek-Amal, Erik C. Neyts, Francois M. Peeters
Summary: Molecular dynamics simulations were conducted to investigate the influence of different cations on the permeation of charged polymers through narrow capillaries. It was discovered that Li+, Na+, and K+ cations, despite being monovalent, have distinct effects on polymer permeation and subsequent transmission speed. This phenomenon was attributed to the interplay between cations' hydration free energies and the hydrodynamic drag experienced by the polymer. Additionally, alkali cations exhibited surface-to-bulk preferences in small water clusters under an external electric field. The paper presents a new approach to controlling the speed of charged polymers in confined spaces using cations.
Article
Engineering, Electrical & Electronic
Sergiu Clima, Taras Ravsher, Daniele Garbin, Robin Degraeve, Andrea Fantini, Romain Delhougne, Gouri Sankar Kar, Geoffrey Pourtois
Summary: Chalcogenides are attractive materials for microelectronics applications due to their ability to change physical, optical, and electrical properties under applied electric stimulus. One recent focus is the use of chalcogenides in the development of a fast and volatile resistance switching device. However, most known materials contain toxic elements, highlighting the need to find environment-friendly alternatives. By using first-principles simulations, we can predict the electrical properties of chalcogenides and identify materials with desired characteristics for specific microelectronics applications.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Michiel J. van Setten, Hendrik F. W. Dekkers, Christopher Pashartis, Adrian Chasin, Attilio Belmonte, Romain Delhougne, Gouri S. Kar, Geoffrey Pourtois
Summary: With the decreasing dimensions and increasing complexity of semiconductor devices, it has become more difficult to fabricate them. Amorphous materials, which do not require annealing steps, are becoming more interesting. However, modeling amorphous materials is more complex than modeling crystalline ones. Therefore, a combination of high throughput first principles calculations and artificial intelligence (AI) is employed to screen for new materials. By training AI models, the properties of ternary and more complex oxides can be predicted based on primary and binary oxide data. This method has been used to identify a metal oxide as a potentially improved alternative to the current industry standard for thin film transistor applications.
MATERIALS ADVANCES
(2022)
Article
Chemistry, Multidisciplinary
Fahim Faraji, Mehdi Neek-Amal, Erik C. Neyts, Francois M. Peeters
Summary: Molecular dynamics simulations were used to investigate the effect of an AFM tip when indenting graphene nano bubbles filled with He, Ne, and Ar gases. The failure points resembled those of viral shells, as described by the Foppl-von Karman (FvK) dimensionless number in the context of elasticity theory. At room temperature, He gas was found to be in the liquid state inside the bubbles, while Ne and Ar atoms were in the solid state, despite the pressure inside the nano bubble being below the melting pressure of the bulk. The trapped gases experienced higher hydrostatic pressure at low temperatures compared to room temperature.