Molecular Dynamics Simulation of Solidification of Ag-x%Au Nanoalloy

2011 ◽  
Vol 312-315 ◽  
pp. 143-148 ◽  
Author(s):  
J. Davoodi ◽  
Leila Mehri

In this investigation, we focus on the glass formation and crystallization process of Ag, Au pure metals as well as Ag-20%Au, Ag-50%Au, and Ag-80%Au (Atoms%) random alloys at the nanoscale. The thermodynamic properties such as solidification temperature and cohesive energy were calculated in the NVT ensemble by the molecular dynamics (MD) simulation technique. The Quantum Sutton-Chen (Q-SC) potential was used to study phase transition and thermal properties of nanoparticles. The temperature dependence of energy was calculated at various concentration of Au. Moreover, the solidification of pure nanoparticles, Ag, Au, and Ag-x%Au nanoalloys were studied at different cooling rates. Our molecular dynamics simulation results show glass structure at fast cooling rates while crystallization at a slow cooling rate. Moreover, the obtained results show that the solidification temperature decreases with decreasing nanoparticle size.

2007 ◽  
Vol 121-123 ◽  
pp. 1053-1056
Author(s):  
Guo Rong Zhong ◽  
Qiu Ming Gao

Molecular dynamics simulation of the solidification behavior of liquid nickel nanowires has been carried out based on the embedded atom potential with different cooling rates. The nanowires constructed with a face-centered cubic structure and a one-dimensional (1D) periodical boundary condition along the wire axis direction. It is found that the final structure of Ni nanowires strongly depend on the cooling rates during solidification from liquid. With decreasing cooling rates the final structure of the nanowires varies from amorphous to crystalline via helical multi-shelled structure.


1996 ◽  
Vol 465 ◽  
Author(s):  
J. M. Delaye ◽  
D. Ghaleb

ABSTRACTIn a simplified (SiO2, B2O3, Na2O, Al2O3, ZrO2) glass, corresponding to the basic matrix for the French nuclear waste containment glass, the authors developed a molecular dynamics simulation of the atom displacement cascades resulting from a disintegration of the actinides. After simulating the secondary cascades resulting from the first atoms displaced by a collision with a recoil nucleus, an actinide (U) was added to the model and the cascade produced by accelerating this type of atom was explicitly investigated, notably to observe the morphological evolution of the cascades and the resulting changes in the glass structure.


2019 ◽  
Vol 486 (2) ◽  
pp. 168-172
Author(s):  
S. A. Rogachev ◽  
A. S. Rogachev ◽  
M. I. Alymov

A molecular dynamics simulation method was applied for estimation of critical cooling rates (vc) that required for amorphization of pure metals: Mg, Al, Ti, Fe, Co, Ni, Cu, Zr, Mo, Pd, Ag, Ta, W, Pt, Au, and Pb. The range of values vc was found to be from 7.9 × 1011 K/s for Al to 3.8 × 1013 K/s for Zr. The atomic structure obtained at different cooling rates is described. A dependence of the specific volume on temperature was investigated both during the amorphization and crystallization processes. The modelling shows, which metals have the highest temperature range of long-term stability of the amorphous phase (Fe, Mo, Ta, W). Estimates were given for the maximum radius of a melt drop that can be cooled at a rate of vc. The obtained simulation results were compared with available experimental data.


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