Molecular-Dynamics Study of the Mechanical Properties of Metallic Nanowires

2002 ◽  
Vol 739 ◽  
Author(s):  
T. Nakajima ◽  
K. Shintani

ABSTRACTThe method of molecular-dynamics is employed to simulate and investigate the deformation of metallic nanowires under tensile strain. The interactions between metallic atoms are calculated by using the embedded-atom method potential. A model nanowire is preliminarily equilibrated at a specified temperature. Then, the uniform uniaxial extension of the nanowire is performed. The thinning process of a metallic nanowire is observed in the sequential snapshots of its morphological change.

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.


2005 ◽  
Vol 475-479 ◽  
pp. 3291-3294
Author(s):  
Shi Fang Xiao ◽  
Yu Hu Wang

The uniaxial compressive mechanical properties of nanocrystalline Fe are simulated with a molecular dynamics technique and the analytical embedded-atom method. An asymmetrical mechanical phenomenon between tensile and compressive process is found, and the yield stress and flow stress in compression are higher than those in tension simulations. The compressive deformation process can be described as three characteristic regions: quasi-elastic deformation, plastic flowing deformation, and strain strengthening. During the plastic flowing deformation region, the material shows very good compressive ductibility. The plastic deformation is mainly dominated by the grain boundary atom slide.


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.


2009 ◽  
Vol 1224 ◽  
Author(s):  
Yoshiaki Kogure ◽  
Toshio Kogugi ◽  
Tadatoshi Nozaki ◽  
Masao Doyama

AbstractAtomistic configuration and motion of dislocation have been simulated by means of molecular dynamics method. The embedded atom method potential for copper is adopted in the simulation. Model crystal is a rectangular solid containing about 140,000 atoms. An edge dislocation is introduced along [112] direction near the center of model crystal, and the system is relaxed. After the dislocation configuration is stabilized, a shear stress is applied and released. Wavy motion of dislocation is developed on the Peierls valleys when the free boundary condition is adopted. Motion of pinned dislocation is also simulated.


2012 ◽  
Vol 184 ◽  
pp. 301-306 ◽  
Author(s):  
Yoshiaki Kogure ◽  
T. Kosugi ◽  
T. Nozaki

Morphology and mechanical resonse of copper nanoparticles with defects have been simulated by means of molecular dynamics simulation. The embedded atom method potential for copper was used to express the interaction of atoms. Four types of model samples were prepared and about 37,000 atoms were contained in each sample. Two of them are cubic shape with {100} surfaces, in which vacancies or interstitials are introduced. The other two samples are once melted and solidified particles with nearly spherical surfaces. The atomic structure is controlled by cooling rate, and crystalline and amorphous structures are realized. Shear and tetragonal strains are applied to the samples and stress-strain relations for the samples are derived. Mechanical damping and internal friction were evaluated from the free decaying oscillations by releasing static strains.


Author(s):  
Tran The Quang ◽  
Vuong Van Thanh ◽  
Do Van Truong

Bi-materials in submicron scale have been widely used in many industries, especially in the microelectronics industry. Due to the different deformation between the two material layers, damage usually occurs on the surface between the two material layers. In this paper, the Molecular dynamics (MD) method is used to investigate the mechanical properties of bi-material Ni/Al under the tensile strain. The examined Ni/Al structure has dimensions of 10.90 nm x 5.27 nm x 4.22 nm/10.93 nm x 5.26 nm x 4.21 nm, with strain rates of 1.83x108s-1, 5.48x108s-1, 1.83x109s-1 and 5.48x109s-1, respectively. The interactions between the atoms in the system are described by the EAM (Embedded Atom Method). The calculated results show that Young's modulus of bi-material Ni/Al does not change under the various strain rates, while the fracture strength of Ni/Al increases with increasing of the strain rates. In addition, the effects of load position and temperature on the fracture strength of Ni/Al are also investigated. With the strain rate of 1.83x108 s-1, the fracture strength of Ni/Al at 100oK and 700oK is 6.6 GPa and 4.3 GPa, respectively. The obtained results of the study are helpful in the design and fabrication of devices based on the bi-material Ni/Al.  


2012 ◽  
Vol 706-709 ◽  
pp. 1337-1342
Author(s):  
Akira Takeuchi ◽  
Akihisa Inoue

Molecular dynamics (MD) simulations were performed for a Zr2Ni alloy by referring to crystallographic features of a metastable Zr2Ni phase. Simulation method was identical to our previous studies named plastic crystal model (PCM), which includes crystallographic operations for an intermetallic compound in terms of the random rotations of hypothetical clusters around their center of gravity and subsequent annealing at a low temperature. On the basis of MD-PCM, the present study considers an additional refinement named united atom scheme (UAS) on the motions of atoms in the hypothetical clusters. In MD-PCM-UAS, Dreiding potential was assigned for atomic bonds in a cluster whereas Generalized Embedded Atom Method potential for the other atomic pairs. The simulation results by MD-PCM-UAS yield a liquid-like structure. However, annealing did not cause subsequent structural relaxation, which differs from the results by MD-PCM and conventional MD simulations. Further simulations based on MD-PCM-UAS were performed for a nanostructure comprising clusters and glue atoms, leading to the best fit with the experimental data.


1996 ◽  
Vol 439 ◽  
Author(s):  
E. Alonso ◽  
M. J. Caturla ◽  
M. Tang ◽  
H. Huang ◽  
T. Diaz de ia Rubia

AbstractHigh-energy cascades have been simulated in gold using molecular dynamics with a modified embedded atom method potential. The results show that both vacancy and interstitial clusters form with high probability as a result of intracascade processes. The formation of clusters has been interpreted in terms of the high pressures generated in the core of the cascade during the early stages. We provide evidence that correlation between interstitial and vacancy clustering exists.


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