AVRAMI–KOLMOGOROV–JOHNSON–MEHL KINETICS FOR NANOPARTICLES

2008 ◽  
Vol 15 (05) ◽  
pp. 605-612 ◽  
Author(s):  
VLADIMIR P. ZHDANOV
Keyword(s):  
Phase Transition ◽  
Activation Energy ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Infinite Medium ◽  
Local State ◽  
Elementary Reaction ◽  
Regular Surface

In the conventional Avrami–Kolmogorov–Johnson–Mehl model, the reaction or phase transition occurring in the 2D or 3D infinite medium is considered to start and proceed around randomly distributed and/or appearing nucleation centers. The radius of the regions transformed is assumed to linearly increase with time. The Monte Carlo simulations presented, illustrate what may happen if the transformation takes place in nanoparticles. The attention is focused on nucleation on the regular surface, edge and corner sites, and on the dependence of the activation energy for elementary reaction events on the local state of the sites.

Transition under noise in the Sznajd model on square lattice

2016 ◽  
Vol 27 (03) ◽  
pp. 1650026 ◽  
Author(s):  
F. W. S. Lima
Keyword(s):  
Phase Transition ◽  
Monte Carlo ◽  
Social Behavior ◽  
Monte Carlo Simulations ◽  
Order Phase Transition ◽  
Opinion Dynamics ◽  
Two Dimensions ◽  
Square Lattice ◽  
Behavior Model ◽  
Second Order Phase Transition

In order to describe the formation of a consensus in human opinion dynamics, in this paper, we study the Sznajd model with probabilistic noise in two dimensions. The time evolution of this system is performed via Monte Carlo simulations. This social behavior model with noise presents a well defined second-order phase transition. For small enough noise q < 0.33 most agents end up sharing the same opinion.

SCREENING PROPERTIES OF HYDROGEN UNDER HIGH PRESSURE

1992 ◽  
Vol 06 (13) ◽  
pp. 811-816 ◽  
Author(s):  
S. L. GARAVELLI ◽  
F. A. OLIVEIRA
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Quantum Monte Carlo ◽  
Critical Pressure ◽  
Quantum Monte Carlo Simulations ◽  
Atomic Phase

In this work we study screening in hydrogen at high pressure. We use a scaling approach to obtain the critical pressure for the atomic phase-molecular phase transition. Our results is in agreement with quantum Monte Carlo simulations.

Surface and size effects on the Ferroelectric Phase Transition and Surface Polarization of Thin Films: Monte Carlo Simulations

1997 ◽  
Vol 493 ◽  
Author(s):  
J. Romero ◽  
L. F. Fonseca
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
First Order ◽  
Surface Polarization ◽  
Ferroelectric Phase Transition Temperature ◽  
Model Hamiltonian

ABSTRACTThe macroscopic polarization of ferroelectric thin films was studied by Monte Carlo simulations using a Transverse Ising Model Hamiltonian with four-spins interactions. The dependence of the ferroelectric phase transition temperature, Tc, on the thickness of the film was obtained resulting in a shifting of Tc towards lower temperatures and a change from first-order to second-order phase transition as the thickness of the film is reduced. Comparison between the surface and internal order was carried out by the calculation of layer-averaged polarizations as a function of the sample temperature and the surface interaction parameters. These comparisons show that increasing disorder at the surface can be reverted by increasing the four-spins surface interactions.

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