Structural and dynamical properties of 13-atom Cu–Co mixed clusters

2021 ◽  
Author(s):  
Shi-Wei Ren
Keyword(s):  
Molecular Dynamics ◽  
Pure Copper ◽  
Similarity Function ◽  
Step Process ◽  
Pure Cobalt ◽  
Pair Separation ◽  
Dynamical Properties ◽  
Mixed Clusters ◽  
Dynamics Method ◽  
Relative Root

In this paper, the geometric structures and the melting-like processes of the 13-atom pure copper, pure cobalt cluster and their 13-atom mixed clusters are investigated and compared by the molecular dynamics method. The calculation shows that the pure copper and cobalt clusters have the standard icosahedral structures and the mixed clusters take on the deformed icosahedral structures. The quantitative analysis shows that the deformations are slight. Moreover, an element similarity function is introduced by which the contribution of the compositions of the clusters to the deformation of the mixed clusters is analyzed and discussed. With the increase of the temperature, the migrating and recombination of the atoms on the surface of the clusters are observed, indicating the starting of the transition from solid-like to liquid-like state for the clusters. Through the calculating of the relative root-mean-squared pair separation fluctuation and monitoring the dynamical structures of the clusters, it is found that the mixed clusters experience a multi-step process in the transition.

Analysis of structures and melting properties of the 19-atom Ni–Co clusters

2014 ◽  
Vol 28 (25) ◽  
pp. 1450171 ◽  
Author(s):  
Shi-Wei Ren ◽  
Jing-Wei Sun ◽  
Yan-Zhong Hao
Keyword(s):  
Melting Temperature ◽  
Nickel Atom ◽  
Melting Temperatures ◽  
Pure Cobalt ◽  
Melting Phenomenon ◽  
Nickel Clusters ◽  
Melting Properties ◽  
Mixed Clusters ◽  
Dynamics Method ◽  
Cobalt And Nickel

In this paper, by using the classical molecular dynamics method and the GEAM potential, the geometric structure and the melting properties of the 19-atom Ni – Co clusters with different compositions are studied. It is found that all the clusters have the double icosahedron structures although some of the structures are slightly deformed. With the increase of the temperature, a pre-melting phenomenon is observed. The pre-melting temperatures of the pure cobalt and nickel clusters are very close. But on the whole, the pre-melting temperature decreases with the increase of the number of the nickel atom for the mixed clusters. The effects of the substitution atoms on the melting temperature of the clusters are similar to that on the pre-melting temperature although there are some oscillations in the decrease process. The mechanism of these findings are also investigated and analyzed.

Study on Dimension Effect of Punch on Nanoimprint Process for Cu-Ni Alloy

2005 ◽  
Author(s):  
Quang-Cherng Hsu ◽  
Cheng-Da Wu ◽  
Te-Hua Fang
Keyword(s):  
Molecular Dynamics ◽  
Size Effect ◽  
Pure Copper ◽  
Molecular Dynamics Method ◽  
Spring Back ◽  
Repulsive Energy ◽  
Ni Alloy ◽  
Relationship Of ◽  
Dynamics Method ◽  
Nano Imprint

The effects of punch size and molding mechanism on the nanoimprint process of Cu(85%)-Ni(15%) alloy were investigated by molecular dynamics method. The distribution for Cu and Ni atoms was random. In order to examine the punch size effect on nanoimprint process, three punch sizes were studied, namely: 3nm × 3nm, 6nm × 6nm and 9nm × 9nm. The results showed that it was difficult for the material to fully fill into die corner, i.e. at non-smooth geometry in the die, during final period of loading. The forming energy and force increased rapidly, because inter-atomic repulsive energy increased as formed pattern became small. It was not successfully imprinted after unloading in the case of 3nm × 3nm, due to larger spring back. Comparing to nano imprint of pure copper, the current study of nano imprint of Cu-Ni alloy presented a cyclically vibrated relationship of force and displacement showing a more complicated interaction between different kinds of atoms.

Study on Interactive Multi-resolution Molecular Dynamics Method

2000 ◽  
Vol 20 (1Supplement) ◽  
pp. 43-46
Author(s):  
Ken-ichi SAITOH ◽  
Takashi DOI ◽  
Masao KOMAYA ◽  
Takehiko INABA
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Method ◽  
Dynamics Method

scholarly journals $$\hbox {Ag}_{m} \hbox {Rh}_n$$ clusters with $$m+n\le 55$$

2021 ◽  
Vol 140 (4) ◽  
Author(s):  
Nicolas Louis ◽  
Stephan Kohaut ◽  
Michael Springborg
Keyword(s):  
Genetic Algorithms ◽  
Structure Optimization ◽  
Structural Similarity ◽  
Similarity Function ◽  
Many Body ◽  
Coordination Numbers ◽  
Energetic Properties ◽  
Ag Clusters ◽  
Body Potential ◽  
Mixed Clusters

AbstractUsing a combination of genetic algorithms for the unbiased structure optimization and a Gupta many-body potential for the calculation of the energetic properties of a given structure, we determine the putative total-energy minima for all $$\hbox {Ag}_{m} \hbox {Rh}_n$$ Ag m Rh n clusters with a total number of atoms $$m+n$$ m + n up to 55. Subsequently, we use various descriptors to analyze the obtained structural and energetic properties. With the help of a similarity function, we show that the pure Ag and Rh clusters are structurally similar for sizes up to around 20 atoms. The same approach gives that the mixed clusters tend to possess a larger structural similarity with the pure Rh clusters than with the pure Ag clusters. However, for clusters with $$m\simeq n\ge 25$$ m ≃ n ≥ 25 , other structures dominate. The effective coordination numbers for the Ag and Rh atoms as well as the radial distributions of those atoms indicate that there is a tendency towards segregation with Rh atoms forming an inner part and the Ag atoms forming a shell. Only few clusters, all with a fairly large total number of atoms, are found to be particularly stable.

Influence of Hole Size on Crack Propagation Mechanism of Nano-Single Crystal Copper

2013 ◽  
Vol 328 ◽  
pp. 679-683
Author(s):  
Ge Li ◽  
Xian Qin Hou ◽  
Zhi Min Liu
Keyword(s):  
Molecular Dynamics ◽  
Crack Propagation ◽  
Hole Diameter ◽  
Propagation Mechanism ◽  
Hole Size ◽  
Single Crystal Copper ◽  
Dislocation Glide ◽  
Hole Position ◽  
Crack Propagation Mechanism ◽  
Dynamics Method

By molecular dynamics method, the tensile processes of nanosingle crystal copper with the crack front existence hole were simulated, and the effect of different hole size on crack propagation mechanism was analyzed. The results indicate that as the hole position remain unchanged, the hole diameter was more bigger, the atomic staggered and the crack tip deactivation were more obvious under tensile loads caused more dislocation glide appeared, meanwhile the number of slide-line was more and the trend of crack branch extend to hole position was more obvious.

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