Material objects with micrometer or nanometer dimensions can exhibit much higher strength than macroscopic objects, but this rarely approaches the maximum theoretical of material. Here, we demonstrate that faceted single-crystalline nickel (Ni) nanoparticles an ultrahigh compressive (up to 34 GPa) unprecedented for metallic materials. This matches available estimates Ni strength. Three factors are responsible record-high strength: large shear modulus, smooth edges and corners nanoparticles,...

Grain boundaries (GBs) are internal interfaces in crystalline materials that control many physical properties. While GBs traditionally described by five crystallographic angles, recent atomistic simulations have shown variations the atomic density \ensuremath{\lambda} of \ensuremath{\Sigma}5 can cause transformations between different GB phases. Here, authors demonstrate multiplicity phases is not specific to particular studied previously. Instead, emergence new a generic phenomenon must...

Molecular dynamics simulations of a quasiharmonic solid are conducted to elucidate the meaning temperature fluctuations in canonical systems and validate well-known but frequently contested equation predicting mean square such fluctuations. The implement two virtual one physical (natural) thermostat examine kinetic, potential, total energy correlation functions time frequency domains. results clearly demonstrate existence quasiequilibrium states which system can be characterized by...

Abstract Interatomic potentials constitute the key component of large-scale atomistic simulations materials. The recently proposed physically-informed neural network (PINN) method combines a high-dimensional regression implemented by an artificial with physics-based bond-order interatomic potential applicable to both metals and nonmetals. In this paper, we present modified version PINN that accelerates training process further improves transferability unknown atomic environments. As...

The classic paradigm of physical metallurgy is that the addition alloying elements to metals increases their strength. It less known if solution-hardening can occur in nano-scale objects, and it totally unknown how impact strength defect-free faceted nanoparticles. Purely metallic nanoparticles exhibit an ultra-high approaching theoretical limit. Tested compression, they deform elastically until nucleation first dislocation, after which collapse into a pancake shape. Here, we show by...

Many grain boundaries (GBs) in crystalline materials develop highly disordered, liquidlike structures at high temperatures. In alloys, this premelting effect can be fueled by solute segregation and occur lower temperatures than single-component systems. A premelted GB modeled a thin liquid layer located between two solid-liquid interfaces interacting disjoining potential. We propose single analytical form of the potential describing repulsive, attractive, intermediate interactions. The...

We perform a systematic study of thermal resistance and conductance tilt grain boundaries (GBs) in Si using classical molecular dynamics. The GBs studied are naturally divided into three groups according to the structural units forming GB core. find that, within each group, conductivity strongly correlates with excess energy. All predict nearly same extrapolated high-energy limit. This limiting value is close amorphous Si, suggesting similar heat transport mechanisms. While lattice decreases...

We derive analytical solutions for the autocorrelation and cross-correlation functions of kinetic, potential, total energy a Langevin oscillator. These are presented in both time frequency domains validated by independent numerical simulations. The results applied to address long-standing issue temperature fluctuations canonical systems.

Previously published data, not ours, on the coarsening of solid \ensuremath{\beta}-Sn particles in a liquid Pb-Sn matrix near-eutectic composition are reanalyzed within framework trans-interface-diffusion-controlled (TIDC) theory coarsening. The data were obtained under conditions microgravity from specimens heat-treated at 458 K and containing four equilibrium volume fractions ${f}_{e}$ equaling 0.10, 0.15, 0.20, 0.30. We show that rate constants $k({f}_{e})$ traditional equation...

Abstract The classic paradigm of physical metallurgy is that the addition alloying elements to metals increases their strength. It less known if solution-hardening can occur in nano-scale objects, and it totally unknown how impact strength defect-free faceted nanoparticles. Purely metallic nanoparticles exhibit an ultra-high approaching theoretical limit. Tested compression, they deform elastically until nucleation first dislocation, after which collapse into a pancake shape. Here, we show...