Berlin 2018 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 8: Topical session (Symposium EPS and MM): Mechanical Properties at Small Scales
MM 8.5: Vortrag
Montag, 12. März 2018, 13:00–13:15, TC 006
Plasticity of silicon at small scale and low temperature: an experimental and numerical study — •Michael Texier1, Amina Merabet1, Firas Abed El Nabi2, Christophe Tromas2, Sandrine Brochard2, Laurent Pizzagalli2, Ludovic Thilly2, Jacques Rabier2, Anne Talneau3, Olivier Thomas1, and Julien Godet2 — 1IM2NP, UMR7334 CNRS - Univ. Aix-Marseille, Marseille, FR — 2Pprime, UPR3346 CNRS - Univ. Poitiers, Futuroscope, FR — 3C2N, Univ. Paris Sud, Orsay, FR
Mechanical properties of silicon have been widely studied in the last decades, but recent studies evidenced that silicon nano-objects behave differently than bulk materials when submitted to mechanical stress. Indeed, for dimensions below a few hundreds of nanometres, a brittle-to-ductile transition (BDT) occurs at room temperature and its origin remains undetermined. Although essential for the Si-based nanotechnologies, the understanding of the microscopic mechanisms responsible for this behavioural change requires to compare results obtained from well-controlled deformation experiments at smallest scales with realistic numerical simulations. In this work, both experimental and numerical nano-compression tests were carried out on similar Si nanopillars. Results obtained from simulations and HRTEM analyses of the deformed specimen disrupt the established description of undissociated-dislocations-mediated plasticity of silicon at low temperatures. This study allows deeply reinterpreting the experimental data recently reported in the literature, and highlights the intricate relationship between BDT, dislocation interactions, and size effect.