Study on the structural transition of CoNi nanoclusters using molecular dynamics simulations

2018 ◽  
Vol 32 (11) ◽  
pp. 1850133
Author(s):  
J. H. Xia ◽  
Xue-Mei Gao

In this work, the segregation and structural transitions of CoNi clusters, between 1500 and 300 K, have been investigated using molecular dynamics simulations with the embedded atom method potential. The radial distribution function was used to analyze the segregation during the cooling processes. It is found that Co atoms segregate to the inside and Ni atoms preferably to the surface during the cooling processes, the Co[Formula: see text]Ni[Formula: see text] cluster becomes a core–shell structure. We discuss the structural transition according to the pair-correction function and pair-analysis technique, and finally the liquid Co[Formula: see text]Ni[Formula: see text] crystallizes into the coexistence of hcp and fcc structure at 300 K. At the same time, it is found that the frozen structure of CoNi cluster is strongly related to the Co concentration.

2017 ◽  
Vol 2 (2) ◽  
pp. 183 ◽  
Author(s):  
Rinaldo Marimpul

Copper film growth using thermal evaporation methods was studied using molecular dynamics simulations. The AlSiMgCuFe modified embedded atom method potential was used to describe interaction of Cu-Cu, Si-Si and Cu-Si atoms. Our results showed that the variations of substrate temperature affected crystal structure composition and surface roughness of the produced copper film catalyst substrate. In this study, we observed intermixing phenomenon after deposition process. The increasing of substrate temperature affected the increasing of the total silicon atoms had diffusion into copper film.


2013 ◽  
Vol 1514 ◽  
pp. 37-42 ◽  
Author(s):  
Prithwish K. Nandi ◽  
Jacob Eapen

ABSTRACTMolecular dynamics simulations are performed to investigate the defect accumulation and microstructure evolution in hcp zirconium (Zr) – a material which is widely used as clad for nuclear fuel. Cascades are generated with a 3 keV primary knock-on atom (PKA) using an embedded atom method (EAM) potential with interactions modified for distances shorter than 0.1 Å. With sequential cascade simulations we show the emergence of stacking faults both in the basal and prism planes, and a Shockley partial dislocation on the basal plane.


2007 ◽  
Vol 539-543 ◽  
pp. 3528-3533
Author(s):  
X.W. Zhou ◽  
D.A. Murdick ◽  
B. Gillespie ◽  
J.J. Quan ◽  
Haydn N.G. Wadley ◽  
...  

The atomic-scale structures and properties of thin films are critically determined by the various kinetic processes activated during their atomic assembly. Molecular dynamics simulations of growth allow these kinetic processes to be realistically addressed at a timescale that is difficult to reach using ab initio calculations. The newest approaches have begun to enable the growth simulation to be applied for a wide range of materials. Embedded atom method potentials can be successfully used to simulate the growth of closely packed metal multilayers. Modified charge transfer ionic + embedded atom method potentials are transferable between metallic and ionic materials and have been used to simulate the growth of metal oxides on metals. New analytical bond order potentials are now enabling significantly improved molecular dynamics simulations of semiconductor growth. Selected simulations are used to demonstrate the insights that can be gained about growth processes at surfaces.


2015 ◽  
Vol 29 (02) ◽  
pp. 1450267
Author(s):  
J. H. Xia ◽  
Xue-mei Gao ◽  
Xu-yang Xiao ◽  
Zheng-fu Cheng

Based on using molecular dynamics simulations, the structural transitions of Co 25 Al 75 and Co 75 Al 25 were studied during two different quenching processes. The pair-correlation function, the Honeycutt–Andersen (HA) pair analysis technique, Voronoi indices and structural snapshot are adopted in both rapid quenching processes. The results provide direct evidence of the liquid–crystal transition and the liquid Co 75 Al 25 crystallizes into bcc phase at 300 K during the rapid quenching process r1 = 1 K/ps. While during the rapid quenching r2 = 10 K/ps the liquid is frozen into the glass state at 300 K. Meanwhile, the liquid Co 25 Al 75 is frozen into the glass state at 300 K during the two rapid quenching processes. Our results show that the phase formation is strongly dependent on the cooling rates and the compositions.


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