Berlin 2018 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 8: Topical session (Symposium EPS and MM): Mechanical Properties at Small Scales

MM 8.3: Talk

Monday, March 12, 2018, 12:30–12:45, TC 006

Atomistic simulations of the mechanical behavior of semiconductor and metallic nanoparticles — Dimitrios Kilymis¹, Sélim Bel Haj Salah¹, Céline Gérard¹, Jonathan Amodeo², and •Laurent Pizzagalli¹ — ¹Institut Pprime, CNRS UPR 3346, Université de Poitiers, Poitiers, 86962, France — ²MATEIS, CNRS UMR 5510, INSA-Lyon Université 1, Villeurbanne, 69621, France

We present the results of molecular dynamics simulations of the mechanical properties of semiconductor and metallic nanoparticles. The aim of the study is to investigate the first stages of plasticity during uniaxial compression while focusing on the influence of the shape (spherical, or facetted, or cubic geometries) and size (from 10 to 50 nm). The nanoparticles are deformed at a constant velocity using flat punch indenters, along different orientations in most of cases. We fully characterize the onset of plasticity, both in terms of yield point and of mechanisms, and examine how those depend on the size and the shape of the nanoparticle. The influence of temperature is also considered. In the case of semiconductor nanoparticles, original plasticity mechanisms are identified, including V-shaped dislocations and an hexagonal phase transition of limited extent. Conversely, for metallic systems, the first plasticity mechanisms are similar to the ones usually activated in bulk. In both cases, it is found that both size and shape effects are significant for the investigated systems.