Molecular dynamics simulation of single crystal copper with silver impurities.


Through molecular dynamics simulations we have investigated the behavior of a single crystal copper dopped with silver impurities (0.1, 0.2 and 0.4 at % Ag) ranged at different temperatures (0.1, 100 and 300 K) under the action the stress tensor . The stress tensor is applied along of the surface in the crystallographic plane(100). Silver atoms are placed randomly on the copper, by replacing. The simulation shows thermodynamic stability properties and altering the sample fractures the crystal structure of this .

Molecular dynamics, impurities, defect of crystal, nanowires of copper.


During the last decade the smaller electronic devices has grown in importance in the market, building nanowires with different metal elements . Increasingly materials with good mechanical properties and electrical conductivity are required(Postma 2005), these studies are necessary to understand the behavior of these in different applications having. Usually the crystal structure of materials are not free of defects , with which one can produce vacancies, dislocations, or impurities in the elements , altering this properties(Rajgarhia 2009)(Rajgarhia 2010)(Amigo 2014). Copper is one of them, for be a ductile and malleable material having a high conductivity but when combined with a crystal of silver with higher conductivity than copper and less hard than this, You will see as influences of these types of defects on the mechanical properties of the material using computational simulation.
Molecular dynamics (MD) is a well-known simulation tool to study materials. This allow us to predict the time evolution of a system under initial conditions ( positions and velocities of all particles in the system) by the use of an interaction potential. The evolution of the system in the time can be followed by solving a set of classical equations of motion for all particles in the system. These correspond to the second law of classical mechanics formulated by Newton(Basic Atomistic Model...): \[\vec{F}_{i}=m_{i}\frac{d^{2}{\vec{r}_i}}{d t^{2}} {\text{; For the $i^{\text{th}}$ particle}}\]

In this paper we collect the study a copper structure with silver impurities under the action and the effect of the stress on the physical and mechanical properties, analyzing point defects in the sample (as partial dislocations). For this we use the method of molecular dynamics submitting the system to uniaxial tensile stress.
This work is organized as follows: in section 2 computational procedure used and the construction of the crystal is explained. In section 3 we present and discuss the results , and finally in Section 4 are given the conclusions of this work.


The system studied consist in a face centred cubic (FCC) crystal of copper with silver impurities at different concentrations (0.1, 0.2 and 0.4 at % Ag). The sample is made of 16000 atoms in a box of 40 \(\times\) 40 \(\times\) 10 in terms of the lattice parameter, which is 3.61 Å for copper(1). In order to incorporate the impurities in the systems, we randomly replace a percentage of cooper atoms by silver atoms. Figure  \ref{structure} show an initial configuration of the used structure.