title: The elastic-plastic transition in nanoparticle collisions.
abstract: When nanoparticles (NPs) collide with low velocities, they interact elastically in the sense that--besides their fusion caused by their mutual van-der-Waals attraction--no defects are generated. We investigate the minimum velocity, vc, necessary for generating defects and inducing plasticity in the NP. The determination of this elastic-plastic threshold is of prime importance for modeling the behavior of granular matter. Using the generic Lennard-Jones interaction potential, we find vc to increase strongly with decreasing radius. Current models do not agree with our simulations, but we provide a model based on dislocation emission in the contact zone that quantitatively describes the size dependence of the elastic-plastic transition.
authors.affiliation: CONICET and Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, 5500 Argentina.
authors.forename: Emmanuel N
authors.initials: EN
authors.lastname: Millán
authors.affiliation: CONICET and Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, 5500 Argentina and Instituto de Bioingeniería, Universidad de Mendoza, Mendoza, M5502BZ Argentina.
authors.forename: Diego R
authors.initials: DR
authors.lastname: Tramontina
authors.affiliation: Physics Department and Research Center OPTIMAS, University Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany. urbassek@rhrk.uni-kl.de.
authors.forename: Herbert M
authors.initials: HM
authors.lastname: Urbassek
authors.affiliation: CONICET and Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, 5500 Argentina.
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Bringa