Microstructure simulations within the Lattice Statics formalism: elasticity and morphologies at the atomic scale

2013 ◽  
Vol 1535 ◽  
Author(s):  
C. Varvenne ◽  
Y. Le Bouar ◽  
A. Finel ◽  
M. Fèvre
Keyword(s):  
Monte Carlo ◽  
Composition Range ◽  
Nucleation And Growth ◽  
Diffusion Time ◽  
Atomic Scale ◽  
Reference State ◽  
Wide Composition Range ◽  
Lattice Statics ◽  
Average Reference ◽  
Effective Pair

ABSTRACTIn this paper, the Lattice Statics formalism is used to perform Monte Carlo simulations of alloy microstructures when elastic effects are present. It provides sets of long-range effective pair interactions (EPIs), defined in a rigid average reference state, that allow us to compute microstructural evolutions on diffusion time scale. A wide composition range is investigated in order to characterize the different precipitation processes with elasticity (nucleation and growth, spinodal decomposition). An advantage of the approach is to include the concentration dependence of both the effective chemical interactions and the elastic properties of the reference state. The importance of this point is illustrated by comparing the precipitation sequences in two alloys with symmetric average concentrations.

Kinetic Monte Carlo Simulation of Impurity Effects on Nucleation and Growth of SiC Clusters on Si(100)

2013 ◽  
Vol 740-742 ◽  
pp. 393-396
Author(s):  
Maxim N. Lubov ◽  
Jörg Pezoldt ◽  
Yuri V. Trushin
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Cluster Size ◽  
Kinetic Monte Carlo ◽  
Nucleation And Growth ◽  
Nucleation Density ◽  
Nucleation Process ◽  
Impurity Effects ◽  
Kinetic Monte Carlo Simulations ◽  
The Mean

The influence of attractive and repulsive impurities on the nucleation process of the SiC clusters on Si(100) surface was investigated. Kinetic Monte Carlo simulations of the SiC clusters growth show that that increase of the impurity concentration (both attractive and repulsive) leads to decrease of the mean cluster size and rise of the nucleation density of the clusters.

In Situ Observation of Nucleation and Growth of Carbon Nanotubes from Iron Carbide Nanoparticles

2008 ◽  
Vol 1142 ◽  
Author(s):  
Hideto Yoshida ◽  
Seiji Takeda ◽  
Tetsuya Uchiyama ◽  
Hideo Kohno ◽  
Yoshikazu Homma
Keyword(s):  
Carbon Nanotubes ◽  
Iron Carbide ◽  
Bulk Diffusion ◽  
Chemical Vapor ◽  
Nucleation And Growth ◽  
Atomic Scale ◽  
In Situ Observation ◽  
Transmission Electron ◽  
Cvd Growth

ABSTRACTNucleation and growth processes of carbon nanotubes (CNTs) in iron catalyzed chemical vapor deposition (CVD) have been observed by means of in-situ environmental transmission electron microscopy. Our atomic scale observations demonstrate that solid state iron carbide (Fe3C) nanoparticles act as catalyst for the CVD growth of CNTs. Iron carbide nanoparticles are structurally fluctuated in CVD condition. Growth of CNTs can be simply explained by bulk diffusion of carbon atoms since nanoparticles are carbide.

Monte Carlo Simulation of Precipitate Nucleation and Growth: Time Dependent Results

1988 ◽  
Vol 141 ◽  
Author(s):  
James P. Lavine ◽  
Gilbert A. Hawkins
Keyword(s):  
Monte Carlo ◽  
Crystalline Silicon ◽  
Three Dimensional ◽  
Nucleation Site ◽  
Nucleation And Growth ◽  
Lattice Points ◽  
Growth Time ◽  
Decay Kinetics ◽  
Time Step ◽  
Oxygen Atoms

AbstractA three-dimensional Monte Carlo computer program has been developed to study the heterogeneous nucleation and growth of oxide precipitates during the thermal treatment of crystalline silicon. In the simulations, oxygen atoms move on a lattice with randomly selected lattice points serving as nucleation sites. The change in free energy that the oxygen cluster would experience in gaining or losing one oxygen atom is used to govern growth or dissolution of the cluster. All the oxygen atoms undergo a jump or a growth decision during each time step of the anneal. The growth and decay kinetics of each nucleation site display interesting fluctuation phenomena. The time dependence of the cluster size generally differs from the expected 3/2 power law due to the fluctuations in oxygen arrival at and incorporation in a precipitate. Competition between growing sites and coarsening are observed.

scholarly journals Test of Anderson-Stuart model in sodium silicate glasses and the general Arrhenian conductivity rule in wide composition range

Cerâmica ◽  
2006 ◽  
Vol 52 (321) ◽  
pp. 22-30 ◽  
Author(s):  
M. L. F. Nascimento ◽  
E. Nascimento ◽  
W. M. Pontuschka ◽  
M. Matsuoka ◽  
S. Watanabe
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Sodium Silicate ◽  
Composition Range ◽  
Absolute Temperature ◽  
Alkali Concentration ◽  
Relative Dielectric Permittivity ◽  
Silicate System ◽  
Wide Composition Range ◽  
Sigma E

We collected and analyzed literature data on ionic conductivity sigma and activation energy E A in the binary sodium silicate system in a wide composition range. The Anderson and Stuart model has been considered to describe the decreasing tendency of activation energy E A with alkali concentration in this system. In this analysis were considered experimental parameters, such as shear modulus G and relative dielectric permittivity epsilon. A general conductivity rule is found in 194 of 205 glasses, when one plots log sigma vs. E A/kB T, where kB is the Boltzmann constant and T is the absolute temperature. This fact means that the arrhenian relation has universal uniqueness of form sigma = sigma (E A,T) in wide Na2O composition range. The results also show that there is strong correlation by more than 19 orders of magnitude on conductivity with E A/kBT. An explanation for this behavior links ionic conductivity and microscopic structure. The problem of phase separation in this system is also considered.

Order and Disorder in Ni-Pt Single Crystals

2011 ◽  
Vol 172-174 ◽  
pp. 593-601 ◽  
Author(s):  
Bernd Schönfeld ◽  
Markus Engelke ◽  
Andrei V. Ruban
Keyword(s):  
Monte Carlo ◽  
Single Crystals ◽  
Nearest Neighbor ◽  
Intermetallic Phase ◽  
Pair Interaction ◽  
Range Order ◽  
Large Contribution ◽  
Local Maxima ◽  
Order And Disorder ◽  
Effective Pair

Single crystals of Ni-25.6 at.% Pt and Ni-87.8 at.% Pt were investigated by diffuse x-ray scattering for states of thermal equilibrium (923 K and 603 K, respectively). The separated short-range order scattering showed local maxima at 100 positions. Effective pair interaction parameters, as determined by the inverse Monte Carlo method, show a strong composition dependence of the nearest-neighbor interaction parameter. First-principles calculations are consistent with this finding and reveal a large contribution due to lattice strain. Based on values of the ordering energy, NiPt3with L12structure was considered as a plausible new intermetallic phase, with Monte Carlo simulations giving an order-disorder transition temperature of 650 K. A single crystal of Ni-75.2 at.% Pt, quenched from 1073 K and aged at 613 K, showed L12-type ordering, reaching a long-range order parameter of 0.50(4) after 800 h.

Atomic Scale Imaging of Nucleation and Growth Trajectories of an Interfacial Bismuth Nanodroplet

ACS Nano ◽  
2016 ◽  
Vol 10 (2) ◽  
pp. 2386-2391 ◽  
Author(s):  
Yingxuan Li ◽  
Benjamin R. Bunes ◽  
Ling Zang ◽  
Jie Zhao ◽  
Yan Li ◽  
...  
Keyword(s):  
Nucleation And Growth ◽  
Atomic Scale ◽  
Growth Trajectories

Structure of liquid Al-Ge-Ni melts in a wide composition range

2019 ◽  
Vol 293 ◽  
pp. 111458
Author(s):  
O.S. Roik ◽  
V.P. Kazimirov ◽  
O.M. Yakovenko ◽  
V.E. Sokolskii ◽  
N.V. Golovataya ◽  
...  
Keyword(s):  
Composition Range ◽  
Wide Composition Range ◽  
Structure Of Liquid
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