Ultimate compressive strength and severe plastic deformation of equilibrated single-crystalline copper nanoparticles

In present study, we adopt molecular dynamics simulations to investigate the influ-ences of typical planar defects, including twin boundaries (TBs), stacking faults (SFs) and grain boundaries (GBs), on the mechanical properties of fcc copper nanoparticles. Groups of nanoparticle samples, including defect-free single crystal and those with specific de-fects, are examined for elastic modulus, yield strength, and deformation mechanisms. De-tailed results reveal that the elastic behavior of nanoparticles can be well described by a modified theoretical model regardless the type of defects. While the planar defects have negligible influence on the elastic modulus, they significantly enhance the yield strength of nanoparticles. Notably, nanoparticles containing fivefold TBs exhibit the highest yield stress, i.e. ~ 17.0 GPa, even surpassing that of the defect-free counterparts, i.e. ~ 10.0 GP. Analysis of atomic deformation unravels that the distinct yielding behaviors are attributed to the activation of different slip systems and the nucleation of dislocations at specific preferential sites. These findings highlight the potential of fabricating planar defects to tailor the mechanical properties of metallic nanoparticles for targeted applications in nano-technology and materials science.

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Hydride Formation Pressures and Kinetics in Individual Pd Nanoparticles with Systematically Varied Levels of Plastic Deformation

Langhammer,

Andersson,

Zimmermann

et al. 2024

Preprint

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Pd nanoparticles, together with bulk and thin film Pd, constitute the archetype model system for metal-hydrogen interactions. The density of defects in Pd nanoparticles, such as grain boundaries and dislocations, combined with their size, shape, composition and lattice strain, dictate their hydrogen sorption kinetics and thermodynamics. Despite decades of research and its relevance in applications, such as solid-state hydrogen storage, hydrogen sensors, hydrogen embrittlement, and hydrogen separation membranes, a coherent picture of the intricate interplay between defects, strain and Pd nanoparticle hydrogen sorption properties is missing. Here, we employ a combination of single particle nanocompression, single particle plasmonic nanoimaging and high-resolution cross-sectional single particle TEM imaging to investigate hydrogen absorption kinetics and hydride phase formation pressures in a nanofabricated array of Pd nanoparticles on sapphire substrate with systematically varied levels of plastic deformation – and thus defects and strain. We not only show a clear deformation-level dependent trend of both the kinetics and the hydride formation pressure, but also reveal their complex evolution upon hydrogen cycling. We discuss how these results provide a quantitative view of the impact of plastic deformation on nanoscale metal hydrides, and how they reveal the surface and bulk morphology of Pd nanoparticles upon repeated hydrogen cycling.

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Ultimate compressive strength and severe plastic deformation of equilibrated single-crystalline copper nanoparticles

Cited by 3 publications

References 43 publications

The effect of composition and long-range order on the strength of defect-free faceted Cu-Au nanoparticles

The effect of composition and long-range order on the strength of defect-free faceted Cu-Au nanoparticles

Influence of planar defects on the mechanical behaviors of spherical metallic nanoparticles

Hydride Formation Pressures and Kinetics in Individual Pd Nanoparticles with Systematically Varied Levels of Plastic Deformation

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