Elastic Properties of Au, Ag, and Core-shell Au@Ag Nanorods from Molecular Dynamics Simulations

Authors U. Shvets, В. Natalich, V. Borysiuk

Sumy State University, 2, Rimsky-Korsakov St., 40007 Sumy, Ukraine

Е-mail v.borisyuk@phe.sumdu.edu.ua
Issue Volume 11, Year 2019, Number 4
Dates Received 07 May 2019; revised manuscript received 02 August 2019; published online 22 August 2019
Citation U. Shvets, В. Natalich, V. Borysiuk, J. Nano- Electron. Phys. 11 No 4, 04026 (2019)
DOI https://doi.org/10.21272/jnep.11(4).04026
PACS Number(s) 02.70.Ns, 62.25. − g
Keywords Molecular dynamics, Nanorod (4) , Core-shell (2) , Young modulus.

We report the computational study of mechanical properties of gold, silver and core-shell Au@Ag nanorods. The dynamical behavior of the samples under tensile deformation was studied within classical molecular dynamics simulation. Interactions between atoms in the samples were described within embedded atom method (EAM) and EAM alloy model for gold – silver interaction in core-shell Au@Ag nanorod. To study the mechanical properties of the nanorods, the tensile deformation procedure was applied to the samples. Stretching of the samples was simulated by displacement of the fixed atoms located in the two external atomic layers at the opposite edges of the samples from each other at constant strain rate of 0.004 ps–1. Temperature of the samples was maintained at 300 K using the Berendsen thermostat through the total simulation time. During the deformation process, mechanical stresses were calculated according to virial theorem for each sample and strain-stress curves were built from obtained data. Obtained strain-stress curves have typical shape with a linear section at the beginning and a further nonlinear part corresponding to plastic deformation. Young moduli of the studied samples were estimated through linear regression of the elastic part of the strain-stress curves. The obtained values are equal to 57.3 GPa, 80.1 GPa and 70.9 GPa for Au@Ag, Au and Ag samples, respectively. Analysis of the snapshots of atomistic configurations shows that considered samples are characterized by different failure dynamics, namely necking was observed only for Au@Ag core-shell nanorod, while pristine gold and silver samples are characterized by failure without clearly visible necking. Comparative analysis of the obtained results shows a good agreement with the similar data available in the literature.

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