Computer Simulation Study of Film Formation Process

1992 ◽  
Vol 280 ◽  
Author(s):  
Yasushi Sasajima ◽  
Syubo Taya ◽  
Satoru Ozawa ◽  
Ryoichi Yamamoto
Keyword(s):  
Formation Process ◽  
Md Simulation ◽  
Film Growth ◽  
Film Formation ◽  
Atomic Structures ◽  
Embedded Atom ◽  
Initial Stage ◽  
The Difference ◽  
Simple Pair ◽  
Eam Potential

ABSTRACTThe initial stage of film formation process was studied by 2 dimensional (2D) Monte-Carlo (MC) simulation and 3D molecular dynamics (MD) simulation. The atomistic interaction was simple pair-wise Lcnnard-Joncs potential for the 2D MC study and embedded atom potential (EAM potential) for the 3D MD simulation. The 2D MC study has revealed the dependence of film growth mode on the potential parameters that correspond to atomic size and binding energy. More realistic MD simulation has been performed using EAM potential for the three kinds of systems, Ni/Cu(111), Ag/Cu(111) and Au/Ni(111). The relaxed atomic structures of such systems showed the difference of atomic combination; coherent interface was obtained for Ni/Cu(111) system, incoherent interface with specific rotational relationships for Ag/Cu(111) andAu/Ni(111).

Different colloidal particle formation process between conjugated polymer and unmodified C60 in preparation of suspension for electrophoretic deposition by reprecipitation method

2021 ◽  
Author(s):  
Kazuya Tada ◽  
Daiya Fujimoto
Keyword(s):  
Molecular Weight ◽  
Electrophoretic Deposition ◽  
Formation Process ◽  
Colloidal Particle ◽  
Film Formation ◽  
Particle Formation ◽  
Large Area ◽  
Significant Difference ◽  
Reprecipitation Method ◽  
The Difference

Abstract Electrophoretic deposition provides material-efficient film formation on large area electrodes. In this study, it has been found that there is a significant difference in the colloidal particle formation process between a thiophene-based copolymer poly(3-octylthiophene- 2,5-diyl-co-3-decyloxythiophene-2,5-diyl) (POT-co-DOT) and C60 in preparation of suspension for electrophoretic deposition by reprecipitation method. This difference is attributed to the difference between low molecular weight materials with specific molecular weight and polymers with molecular weight distribution. The composition of POT-co-DOT:C60 composite film by electrophoretic deposition has also been estimated.

scholarly journals A numerical fitting procedure for the embedded atom method interatomic potential and a bridged finite element-molecular dynamics method for large atomic systems

2021 ◽  
Author(s):  
Karthik Narayan
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Embedded Atom Method ◽  
Discretization Scheme ◽  
Element Discretization ◽  
Atomic Systems ◽  
Embedded Atom ◽  
Fitting Procedure ◽  
Numerical Fitting ◽  
Eam Potential

This thesis presents a powerful numerical fitting procedure for generating Embedded Atom Method (EAM) inter-atomic potentials for pure Face Centred Cubic (FCC) and Body Centred Cubic (BCC) metals. The numerical fitting procedure involves assuming a reasonable parameterized form for a portion of the EAM potential, and then fitting the remaining portion to select thermal and elastic properties of the metal. Molecular Dynamics (MD) simulation is used to effect the fitting procedure. The procedure is used to generate an EAM potential for copper, an FCC metal. This resulting EAM potential is used to conduct MD simulations of perfect copper crystals containing voids of different geometries. Following this, a bridged Finite Element-Molecular Dynamics (FE-MD) method is presented, which can be used to simulate large atomic systems much more efficiently than MD simulation alone. The method implements a novel element discretization scheme proposed by the author that is so general that it can be applied to any system of objects interacting with each other via any potential (simple or complex, EAM or otherwise). This bridged FE-MD method is used to reanalyze the voids in the copper crystal lattice. The resulting virial stress increment patterns are found to agree remarkably with the earlier MD simulation results. Furthermore, the bridged FE-MD method is much quicker than the pure MD simulation. These two facts prove the power and usefulness of the bridged FE-MD method, and validate the proposed element discretization scheme

Computer Simulation Study of Thin Film Formation Process

1990 ◽  
Vol 187 ◽  
Author(s):  
Yasushi Sasajima ◽  
Satoru Ozawa ◽  
Ryoichi Yamamoto
Keyword(s):  
Thin Film ◽  
Hybrid Method ◽  
Formation Process ◽  
Md Simulation ◽  
Film Formation ◽  
Film Structure ◽  
High Rate ◽  
Atomic Interaction ◽  
Reconstruction Process ◽  
Thin Film Formation

AbstractThe thin film formation process was studied by the molecular dynamics(MD) method and by the hybrid method which combined the MD method with the Monte Carlo(MC) simulation technique. The Morse potential was assumed as the atomic interaction model. The substrate temperature was changed to see its effect on the film structure. The MD simulation found that the reconstruction process of the deposited nuclei was essential to determine the metastable film structure and that the relaxed atomic arrangements were strongly dependent on the depth of the interaction potentials. The hybrid method simulated the high rate deposition process and confirmed the results of the MD simulation.

Influence of Water-Splash Formation by a Hydrophilic Body Plunging Into Water

2011 ◽  
Author(s):  
Yoshihiro Kubota ◽  
Osamu Mochizuki
Keyword(s):  
Formation Process ◽  
High Speed ◽  
Film Formation ◽  
Water Film ◽  
Acrylic Resin ◽  
The Body ◽  
Water Splash ◽  
The Difference ◽  
Film Separation ◽  
The Relationship

The objective of this study is to understand the relationship between water-splash formation and the surface conditions of bodies plunging into the water’s surface by considering hydrophilicity strength. A hydrophilic body (constructed with hydrogel), as well as an acrylic resin body, was created to understand the influence of hydrophilicity on splash formation. The strength of hydrophilicity was determined by investigating degrees of swelling. We obtained consecutive images of splash formation by using a high-speed CMOS camera. We show that water-splash formation is related to water-film formation by studying: 1) droplets formed at the film edge, 2) mushroom-or dome-type splashes caused by film impinging, and 3) crown-type splash caused by film separation. The strength of hydrophilicity affects the splash-formation process of the mushroom- and crown-type splashes. The difference in formation process is caused when the film velocity increases with hydrophilicity. As the film velocity increases with strong hydrophilicity, the film flow separates from the body surface and an air cavity forms. Crown-type splashes form with hydrophilic bodies because such film separation occurs. Moreover, the relationship between the strength of hydrophilicity and film velocity was examined empirically. These results indicate that the hydrophilic body does not alter the splash-formation process.

NiAl thin film growth on Ni(001) substrate using molecular dynamics simulations

2020 ◽  
Vol 91 (3) ◽  
pp. 30301
Author(s):  
Hicham El Azrak ◽  
Abdessamad Hassani ◽  
Khalid Sbiaai ◽  
Abdellatif Hasnaoui
Keyword(s):  
Thin Film ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Film Growth ◽  
Deposition Process ◽  
Thin Film Growth ◽  
Embedded Atom ◽  
Dynamics Simulations ◽  
Eam Potential ◽  
Deposited Film

We have studied thin film growth of NiAl on Nickel (001) substrate using molecular dynamics simulations (MD) based on the Embedded Atom Method (EAM) potential. An incidence energy of 0.06 eV at 800 K, 900 K and 1000 K was considered. After the deposition process, we have obtained a B2-NiAl structure film with different percentages; 32.6% for the temperature 1000 K, 30% for 900 K and 25% for 800 K. Our investigation has prompt us to analyze the crystalline structure. During the evolution of deposited film, we observe the formation of grains with different orientation, as well as the appearance of vacancies in Ni and Al sublattices and antisites.

scholarly journals A numerical fitting procedure for the embedded atom method interatomic potential and a bridged finite element-molecular dynamics method for large atomic systems

2021 ◽  
Author(s):  
Karthik Narayan
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Embedded Atom Method ◽  
Discretization Scheme ◽  
Element Discretization ◽  
Atomic Systems ◽  
Embedded Atom ◽  
Fitting Procedure ◽  
Numerical Fitting ◽  
Eam Potential

This thesis presents a powerful numerical fitting procedure for generating Embedded Atom Method (EAM) inter-atomic potentials for pure Face Centred Cubic (FCC) and Body Centred Cubic (BCC) metals. The numerical fitting procedure involves assuming a reasonable parameterized form for a portion of the EAM potential, and then fitting the remaining portion to select thermal and elastic properties of the metal. Molecular Dynamics (MD) simulation is used to effect the fitting procedure. The procedure is used to generate an EAM potential for copper, an FCC metal. This resulting EAM potential is used to conduct MD simulations of perfect copper crystals containing voids of different geometries. Following this, a bridged Finite Element-Molecular Dynamics (FE-MD) method is presented, which can be used to simulate large atomic systems much more efficiently than MD simulation alone. The method implements a novel element discretization scheme proposed by the author that is so general that it can be applied to any system of objects interacting with each other via any potential (simple or complex, EAM or otherwise). This bridged FE-MD method is used to reanalyze the voids in the copper crystal lattice. The resulting virial stress increment patterns are found to agree remarkably with the earlier MD simulation results. Furthermore, the bridged FE-MD method is much quicker than the pure MD simulation. These two facts prove the power and usefulness of the bridged FE-MD method, and validate the proposed element discretization scheme

Is there a Limit to Nanoscale Mechanical Machining?

2013 ◽  
Vol 581 ◽  
pp. 316-321
Author(s):  
Akinjide O. Oluwajobi ◽  
Xun Chen
Keyword(s):  
Material Removal ◽  
Md Simulation ◽  
Depth Of Cut ◽  
Embedded Atom Method ◽  
Guiding Principle ◽  
Lennard Jones ◽  
Embedded Atom ◽  
Removal Processes ◽  
Mechanical Machining ◽  
Eam Potential

The Moores law which predicts that the number of transistors which can be integrated on the computer chip will double every 24 months and which has been the guiding principle for the advancement of the computer industry, is gradually reaching its limit. This is due to the limitations imposed by the laws of physics. Similarly, in the machining sector, Taniguchi predicted an increasing achievable machining precision as a function of time in the 1980s and this prediction is still on course. The question also is, is there a limit to machining and to material removal processes; and how far can this prediction be sustained? In this paper, the molecular dynamics (MD) simulation was employed to investigate this limit in the nanomachining of a copper workpiece with a diamond tool. The variation of the depth of cut used was from 0.01nm to 0.5nm. The Embedded Atom Method (EAM) potential was used for the copper-copper interactions in the workpiece; the Lennard-Jones (LJ) potential was used for the copper-carbon (workpiece-tool interface) interactions and the tool (carbon-carbon interactions) was modelled as deformable by using the Tersoff potential. It was observed from the simulation results that no material removal occurred between 0.01nm 0.25nm depth. At the depth of cut of 0.3nm, a layer of atoms appears to be removed or ploughed through by the tool. At a depth of cut less than 0.3nm, the other only phenomenon observed was the squeezing of the atom. The 0.3nm depth of cut is around the diameter of the workpiece-copper atom. So, it may be suggested that the limit of machining may be the removal of the atom of the workpiece.

Local atomic structure in tetragonal pure ZrO2nanopowders

2010 ◽  
Vol 43 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Leandro M. Acuña ◽  
Diego G. Lamas ◽  
Rodolfo O. Fuentes ◽  
Ismael O. Fábregas ◽  
Márcia C. A. Fantini ◽  
...  
Keyword(s):  
Tetragonal Phase ◽  
Local Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Crystallite Sizes ◽  
Exafs Study ◽  
The Difference ◽  
X Ray Absorption ◽  
Good Agreement

The local atomic structures around the Zr atom of pure (undoped) ZrO2nanopowders with different average crystallite sizes, ranging from 7 to 40 nm, have been investigated. The nanopowders were synthesized by different wet-chemical routes, but all exhibit the high-temperature tetragonal phase stabilized at room temperature, as established by synchrotron radiation X-ray diffraction. The extended X-ray absorption fine structure (EXAFS) technique was applied to analyze the local structure around the Zr atoms. Several authors have studied this system using the EXAFS technique without obtaining a good agreement between crystallographic and EXAFS data. In this work, it is shown that the local structure of ZrO2nanopowders can be described by a model consisting of two oxygen subshells (4 + 4 atoms) with different Zr—O distances, in agreement with those independently determined by X-ray diffraction. However, the EXAFS study shows that the second oxygen subshell exhibits a Debye–Waller (DW) parameter much higher than that of the first oxygen subshell, a result that cannot be explained by the crystallographic model accepted for the tetragonal phase of zirconia-based materials. However, as proposed by other authors, the difference in the DW parameters between the two oxygen subshells around the Zr atoms can be explained by the existence of oxygen displacements perpendicular to thezdirection; these mainly affect the second oxygen subshell because of the directional character of the EXAFS DW parameter, in contradiction to the crystallographic value. It is also established that this model is similar to another model having three oxygen subshells, with a 4 + 2 + 2 distribution of atoms, with only one DW parameter for all oxygen subshells. Both models are in good agreement with the crystal structure determined by X-ray diffraction experiments.

scholarly journals Paint Film Formation Process in Spray Coating

1986 ◽  
Vol 59 (12) ◽  
pp. 711-718 ◽  
Author(s):  
Kazuyuki TACHI ◽  
Chikaaki OKUDA ◽  
Yoichi OYAMA ◽  
Shouichi SUZUKI
Keyword(s):  
Formation Process ◽  
Film Formation ◽  
Paint Film ◽  
Spray Coating
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