Computer Simulation of the Migration Of Self-Interstitial Atoms in Alpha-Zirconium

1996 ◽  
Vol 439 ◽  
Author(s):  
B. J. Whiting ◽  
D. J. Bacon
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Low Temperature ◽  
Basal Plane ◽  
Interatomic Potential ◽  
Many Body ◽  
Dynamics Model ◽  
Strong Anisotropy ◽  
Displacement Cascades ◽  
Different Temperatures

AbstractThe migration of single interstitials and small interstitial clusters in ox-zirconium at different temperatures has been analysed using a molecular dynamics model with a many-body interatomic potential. The migration exhibits a strong anisotropy. The defects are very mobile (with Em = 0. 01 eV) along <1120> directions in the basal plane, and this motion is dominant for the single interstitial at low temperature and the di- and tri-interstitials at all temperatures. Above about 500 K, the single interstitial exhibits 2-D and 3-D motion, but Em for non-basal motion is about 0.133 eV. These results point to important consequences for the behaviour of defects formed by displacement cascades in irradiated zirconium.

THE EFFECT OF PBC ON THE SIMULATION OF NANOTUBES

2000 ◽  
Vol 11 (03) ◽  
pp. 547-551 ◽  
Author(s):  
ŞAKIR ERKOÇ
Keyword(s):  
Molecular Dynamics ◽  
Boundary Condition ◽  
Computer Simulation ◽  
Carbon Nanotube ◽  
Low Temperature ◽  
Periodic Boundary Condition ◽  
Periodic Boundary ◽  
Potential Energy Function ◽  
Many Body ◽  
Body Potential

The effect of the periodic boundary condition (PBC) on the structure and energetics of nanotubes has been investigated by performing molecular-dynamics computer simulation. Calculations have been realized by using an empirical many-body potential energy function for carbon. A single-wall carbon nanotube has been considered in the simulations. It has been found that the periodic boundary condition has no effect at low temperature (1 K), however, it plays an important role even at intermediate temperature (300 K).

Computer simulation of point defect properties in dilute Fe—Cu alloy using a many-body interatomic potential

1997 ◽  
Vol 75 (3) ◽  
pp. 713-732 ◽  
Author(s):  
G. J. Ackland ◽  
D. J. Bacon ◽  
A. F. Calder ◽  
T. Harry
Keyword(s):  
Computer Simulation ◽  
Point Defect ◽  
Interatomic Potential ◽  
Many Body ◽  
Cu Alloy

COMPUTER SIMULATION OF EPITAXIAL GROWTH OF SILICON ON Si (001) SURFACE

2002 ◽  
Vol 16 (01n02) ◽  
pp. 227-232 ◽  
Author(s):  
M. H. LIANG ◽  
X. XIE ◽  
S. LI
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Epitaxial Growth ◽  
Interatomic Potential ◽  
Simulation Method ◽  
Growth Direction ◽  
Dynamics Simulation ◽  
Interatomic Potentials ◽  
Weber Potential ◽  
Deposition Conditions

Epitaxial growth of silicon on Si (001) surface has been studied with interatomic potential based molecular dynamics simulation method. Three silicon interatomic potentials developed separately by Stillinger-Weber, Tersoff, and Bazant-Kaxiras were used. Energetic beam of 8 eV, substrate temperature of 500K and deposition rate of 1.15 ps/atom were used as the deposition conditions. Morphologies of the growth were obtained and densities in the growth direction analyzed. Epitaxial growth under the deposition conditions imposed was found possible only using the Stillinger-Weber potential. Disordered growths of differing degree were obtained using the Bazant-Kaxiras and Tersoff potentials. The disordered growth may be attributed to the existence of an epitaxial transition temperature higher than 500K that these potentials might have.

Effect of the interatomic potential on the features of displacement cascades in α-Fe: A molecular dynamics study

2006 ◽  
Vol 351 (1-3) ◽  
pp. 65-77 ◽  
Author(s):  
D. Terentyev ◽  
C. Lagerstedt ◽  
P. Olsson ◽  
K. Nordlund ◽  
J. Wallenius ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Interatomic Potential ◽  
Displacement Cascades

H Motion in Pd and Nb: A Molecular-Dynamics Study

1992 ◽  
Vol 291 ◽  
Author(s):  
Yinggang Li ◽  
Göran Wahnström
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Detailed Comparison ◽  
Scattering Data ◽  
Many Body ◽  
Different Temperatures ◽  
Quasielastic Neutron ◽  
Nonadiabatic Effects ◽  
Quasielastic Neutron Scattering ◽  
Dynamics Simulations

ABSTRACTBased on realistic many-body potentials molecular-dynamics simulations are carried out for PdH0.03 and NbH0.02. The H motion is investigated at two different temperatures, T = 300 and 600K, paying attention to the vibrational and diffusive motion. We find that the motion of H in Nb, a bcc metal, is more complicated than in Pd, a fee metal, and the differences are discussed. When detailed comparison is made with quasielastic neutron scattering data for H in Pd at 600K, we argue that in order to characterize the diffusion correctly, one has to include nonadiabatic effects.

TEMPERATURE DEPENDENCE STUDY OF NONCONTACT AFM IMAGES USING MOLECULAR DYNAMICS SIMULATIONS

2012 ◽  
Vol 05 ◽  
pp. 418-432 ◽  
Author(s):  
HOSSEIN NEJAT PISHKENARI ◽  
ALI MEGHDARI
Keyword(s):  
Molecular Dynamics ◽  
Interatomic Potential ◽  
Close Approach ◽  
Atomic Scale ◽  
Effect Of Temperature ◽  
Force Microscopy ◽  
Atomic Force ◽  
Different Temperatures ◽  
Dynamics Simulations ◽  
Noncontact Afm

The effect of temperature on the noncontact atomic force microscopy (NC-AFM) surface imaging is investigated with the aid of molecular dynamics (MD) analysis based on the Sutton-Chen (SC) interatomic potential. Particular attention is devoted to the tip and sample flexibility at different temperatures. When a gold coated probe is brought close to the Au (001) surface at high temperatures, the tip and surface atoms are pulled together and their distance becomes smaller. The tip and sample atoms displacement varies in the different environment temperatures and this leads to the different interaction forces. Along this line, to study the effect of temperature on the resulting images, we have employed the well-known NC-AFM model and carried out realistic non-equilibrium MD 3D simulations of atomic scale imaging at different close approach positions to the surface.

scholarly journals Computer Simulation of the Effect of Copper on Defect Production and Damage Evolution in Ferritic Steels

1999 ◽  
Vol 578 ◽  
Author(s):  
J. M. Perlado ◽  
J. Marian ◽  
D. Lodi ◽  
T. Díaz De La Rubia
Keyword(s):  
Interatomic Potential ◽  
Substantial Effect ◽  
Dislocation Motion ◽  
Many Body ◽  
Displacement Cascades ◽  
Self Diffusion ◽  
Surrounding Matrix ◽  
Pressure Vessel Steels ◽  
Solute Atoms ◽  
Effect Of Copper

AbstractIt has long been noticed that the effect of Cu solute atoms is important for the microstructural evolution of ferritic pressure vessel steels under neutron irradiation conditions. Despite the low concentration of Cu in steel, Cu precipitates form inside the α-Fe surrounding matrix and by impeding free dislocation motion considerably contribute to the hardening of the material. It has been suggested that Cu-rich clusters and combined Cu solute atoms-defect clusters that may act as initiating structures of further precipitates nucleate during annealing of displacement cascades. In order to assess the importance of the different mechanisms taking place during collision events in the formation and later evolution of these structures, a detailed Molecular Dynamics (MD) analysis of displacement cascades in a Fe-1.3% at. Cu binary alloy has been carried out. Cascade energies ranging from 1 to 20 keV have been simulated at temperatures of 100 and 600 K using the MDCASK code, in which the Ackland-Finnis-Sinclair many-body interatomic potential has been implemented. The behaviour of metastable Cu selfinterstitial atoms (SIAs) in the form of mixed Fe-Cu features is studied as well as their impact on the resulting defect structures. It is observed that above 300 K generated Cu SIAs undergo recombination with no substantial effect on the after-cascade microstructure while at 100 K Cu SIAs remain sessile and exhibit a considerable binding to interstitial and vacancy clusters. Finally, the effect that the production of vacancies via collision cascades may have on the self diffusion of Cu solute atoms is quantitatively addressed by means of determining diffusion coefficients for Cu atoms under different microstructural conditions.

STRUCTURAL PROPERTIES OF CARBON NANORODS: MOLECULAR-DYNAMICS SIMULATIONS

2002 ◽  
Vol 13 (03) ◽  
pp. 367-373 ◽  
Author(s):  
ŞAKIR ERKOÇ ◽  
OSMAN BARIŞ MALCIOĞLU
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Low Temperature ◽  
Potential Energy ◽  
Computer Simulations ◽  
Energy Function ◽  
Potential Energy Function ◽  
Many Body ◽  
Dynamics Simulations ◽  
Body Potential

The formation of carbon nanorods from various types of carbon nanotubes has been investigated by performing molecular-dynamics computer simulations. Calculations have been realized by using an empirical many-body potential energy function for carbon. It has been found that carbon nanorod formed from carbon nanotubes with different chirality is not stable even at low temperature.

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