Self-Replicating Twins in Nanowires

Based on molecular-dynamics simulations validated with quantum-mechanical calculations, we predict that (111) twin planes in a [111]-oriented GaAs nanowire attain attractive interactions mediated by surface strain. This gives rise to a self-replication mechanism that continuously generates a twin superlattice in a nanowire during growth. We demonstrate significant implications of the twin–twin interaction for the electronic, mechanical, and chemical properties of nanowires. These unique properties suggest potential applications such as catalysts for solar fuel production and nanoscale mechanical dampers

Decaheme Cytochrome MtrF Adsorption and Electron Transfer on Gold Surface

Emergent electrical properties of multiheme cytochromes have promising applications. We performed hybrid simulations (molecular dynamics, free energy computation, and kinetic Monte Carlo) to study decaheme cytochrome, MtrF adsorption on an Au (111) surface in water and the electron transfer (ET) efficiency. Our results reveal that the gold surface’s dehydration serves as a crucial driving force for protein adsorption due to large surface tension. The most possible adsorption orientation is with the ET terminal (heme5) approaching the gold surface, which yields a pathway for ET between the substrate and the aqueous environment. Upon adsorption, protein’s secondary structures and central domains (II and IV) bonded with heme-residues remain relatively stable. MtrF surface mobility is dictated by thiol-gold interaction and strong binding between Au(111) and peptide aromatic groups. ET transfer rate across protein heme-network along the solvent-to-surface direction is slightly larger than that of the reverse direction, but lower than that of the solvation structure

Faceting, Grain Growth, and Crack Healing in Alumina

Reactive molecular dynamics simulations are performed to study self-healing of cracks in Al₂O₃ containing core/shell SiC/SiO₂ nanoparticles. These simulations are carried out in a precracked Al₂O₃ under mode 1 strain at 1426 °C. The nanoparticles are embedded ahead of the precrack in the Al₂O₃ matrix. When the crack begins to propagate at a strain of 2%, the nanoparticles closest to the advancing crack distort to create nanochannels through which silica flows toward the crack and stops its growth. At this strain, the Al₂O₃ matrix at the interface of SiC/SiO₂ nanoparticles forms facets along the prismatic (A) ⟨2̅110⟩ and prismatic (M) ⟨1̅010⟩ planes. These facets act as nucleation sites for the growth of multiple secondary amorphous grains in the Al₂O₃ matrix. These grains grow with an increase in the applied strain. Voids and nanocracks form in the grain boundaries but are again healed by diffusion of silica from the nanoparticles

Faceting, Grain Growth, and Crack Healing in Alumina

Reactive molecular dynamics simulations are performed to study self-healing of cracks in Al₂O₃ containing core/shell SiC/SiO₂ nanoparticles. These simulations are carried out in a precracked Al₂O₃ under mode 1 strain at 1426 °C. The nanoparticles are embedded ahead of the precrack in the Al₂O₃ matrix. When the crack begins to propagate at a strain of 2%, the nanoparticles closest to the advancing crack distort to create nanochannels through which silica flows toward the crack and stops its growth. At this strain, the Al₂O₃ matrix at the interface of SiC/SiO₂ nanoparticles forms facets along the prismatic (A) ⟨2̅110⟩ and prismatic (M) ⟨1̅010⟩ planes. These facets act as nucleation sites for the growth of multiple secondary amorphous grains in the Al₂O₃ matrix. These grains grow with an increase in the applied strain. Voids and nanocracks form in the grain boundaries but are again healed by diffusion of silica from the nanoparticles

Faceting, Grain Growth, and Crack Healing in Alumina

Reactive molecular dynamics simulations are performed to study self-healing of cracks in Al₂O₃ containing core/shell SiC/SiO₂ nanoparticles. These simulations are carried out in a precracked Al₂O₃ under mode 1 strain at 1426 °C. The nanoparticles are embedded ahead of the precrack in the Al₂O₃ matrix. When the crack begins to propagate at a strain of 2%, the nanoparticles closest to the advancing crack distort to create nanochannels through which silica flows toward the crack and stops its growth. At this strain, the Al₂O₃ matrix at the interface of SiC/SiO₂ nanoparticles forms facets along the prismatic (A) ⟨2̅110⟩ and prismatic (M) ⟨1̅010⟩ planes. These facets act as nucleation sites for the growth of multiple secondary amorphous grains in the Al₂O₃ matrix. These grains grow with an increase in the applied strain. Voids and nanocracks form in the grain boundaries but are again healed by diffusion of silica from the nanoparticles

Faceting, Grain Growth, and Crack Healing in Alumina

Reactive molecular dynamics simulations are performed to study self-healing of cracks in Al₂O₃ containing core/shell SiC/SiO₂ nanoparticles. These simulations are carried out in a precracked Al₂O₃ under mode 1 strain at 1426 °C. The nanoparticles are embedded ahead of the precrack in the Al₂O₃ matrix. When the crack begins to propagate at a strain of 2%, the nanoparticles closest to the advancing crack distort to create nanochannels through which silica flows toward the crack and stops its growth. At this strain, the Al₂O₃ matrix at the interface of SiC/SiO₂ nanoparticles forms facets along the prismatic (A) ⟨2̅110⟩ and prismatic (M) ⟨1̅010⟩ planes. These facets act as nucleation sites for the growth of multiple secondary amorphous grains in the Al₂O₃ matrix. These grains grow with an increase in the applied strain. Voids and nanocracks form in the grain boundaries but are again healed by diffusion of silica from the nanoparticles

Pressure-Controlled Layer-by-Layer to Continuous Oxidation of ZrS₂(001) Surface

Understanding oxidation mechanisms of layered semiconducting transition-metal dichalcogenides (TMDC) is important not only for controlling native oxide formation but also for synthesis of oxide and oxysulfide products. Here, reactive molecular dynamics simulations show that oxygen partial pressure controls not only the ZrS2 oxidation rate but also the oxide morphology and quality. We find a transition from layer-by-layer oxidation to amorphous-oxide-mediated continuous oxidation as the oxidation progresses, where different pressures selectively expose different oxidation stages within a given time window. While the kinetics of the fast continuous oxidation stage is well described by the conventional Deal–Grove model, the layer-by-layer oxidation stage is dictated by reactive bond-switching mechanisms. This work provides atomistic details and a potential foundation for rational pressure-controlled oxidation of TMDC materials

Pressure-Controlled Layer-by-Layer to Continuous Oxidation of ZrS₂(001) Surface

Understanding oxidation mechanisms of layered semiconducting transition-metal dichalcogenides (TMDC) is important not only for controlling native oxide formation but also for synthesis of oxide and oxysulfide products. Here, reactive molecular dynamics simulations show that oxygen partial pressure controls not only the ZrS2 oxidation rate but also the oxide morphology and quality. We find a transition from layer-by-layer oxidation to amorphous-oxide-mediated continuous oxidation as the oxidation progresses, where different pressures selectively expose different oxidation stages within a given time window. While the kinetics of the fast continuous oxidation stage is well described by the conventional Deal–Grove model, the layer-by-layer oxidation stage is dictated by reactive bond-switching mechanisms. This work provides atomistic details and a potential foundation for rational pressure-controlled oxidation of TMDC materials

Pressure-Controlled Layer-by-Layer to Continuous Oxidation of ZrS₂(001) Surface

Understanding oxidation mechanisms of layered semiconducting transition-metal dichalcogenides (TMDC) is important not only for controlling native oxide formation but also for synthesis of oxide and oxysulfide products. Here, reactive molecular dynamics simulations show that oxygen partial pressure controls not only the ZrS2 oxidation rate but also the oxide morphology and quality. We find a transition from layer-by-layer oxidation to amorphous-oxide-mediated continuous oxidation as the oxidation progresses, where different pressures selectively expose different oxidation stages within a given time window. While the kinetics of the fast continuous oxidation stage is well described by the conventional Deal–Grove model, the layer-by-layer oxidation stage is dictated by reactive bond-switching mechanisms. This work provides atomistic details and a potential foundation for rational pressure-controlled oxidation of TMDC materials

Pressure-Controlled Layer-by-Layer to Continuous Oxidation of ZrS₂(001) Surface

Understanding oxidation mechanisms of layered semiconducting transition-metal dichalcogenides (TMDC) is important not only for controlling native oxide formation but also for synthesis of oxide and oxysulfide products. Here, reactive molecular dynamics simulations show that oxygen partial pressure controls not only the ZrS2 oxidation rate but also the oxide morphology and quality. We find a transition from layer-by-layer oxidation to amorphous-oxide-mediated continuous oxidation as the oxidation progresses, where different pressures selectively expose different oxidation stages within a given time window. While the kinetics of the fast continuous oxidation stage is well described by the conventional Deal–Grove model, the layer-by-layer oxidation stage is dictated by reactive bond-switching mechanisms. This work provides atomistic details and a potential foundation for rational pressure-controlled oxidation of TMDC materials