scholarly journals Grain Boundary Propagation and Epitaxy on (111) Surfaces of FCC Substrates: A Kinetic Monte Carlo Study with Lennard-Jones and Iridium Potentials

2021 ◽  
Author(s):  
◽  
David John Williamson
Keyword(s):  
Monte Carlo ◽  
Grain Boundary ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Study ◽  
Scanning Tunneling ◽  
Surface Barrier ◽  
High Deposition Rate ◽  
Tunneling Microscopy ◽  
Elastic Band ◽  
Lennard Jones

<p>A Kinetic Monte Carlo (KMC) method was developed to model homoepitaxy and grain boundary propagation on a (111) surface. Barrier energies were calculated using the Nudged Elastic Band (NEB) technique. A recently reported inertial relaxation technique named FIRE (the Fast Inertial Relaxation Engine) was used to relax the NEB images. Both the Lennard-Jones potential and a Sutton-Chen Iridium potential were used and compared. A doubly-refined lattice mesh was developed to incorporate atoms in Face-Centred-Cubic (FCC) and Hexagonal-Close-Packed (HCP) sites as well as atoms in decorated row sites (i.e. supported by 4 atoms). A look-up table was developed to identify hops in the KMC algorithm. The KMC results show that a small difference in energy barriers between FCC and HCP sites on the substrate can cause a substantial bias in the direction of grain boundary propagation. We also investigated the effect of the geometry of the grain boundary on its propagation, as well as the atomistic processes involved in grain boundary propagation and the merger of grain boundaries. Our deposition simulations produced islands with loosely triangular envelopes, where FCC islands are rotated 180° with respect to HCP islands. The results are similar to scanning tunneling microscopy (STM) images of Iridium deposition, although lack of computing power forced us to use a high deposition rate and this caused some differences.</p>

scholarly journals Grain Boundary Propagation and Epitaxy on (111) Surfaces of FCC Substrates: A Kinetic Monte Carlo Study with Lennard-Jones and Iridium Potentials

2021 ◽  
Author(s):  
◽  
David John Williamson
Keyword(s):  
Monte Carlo ◽  
Grain Boundary ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Study ◽  
Scanning Tunneling ◽  
Surface Barrier ◽  
High Deposition Rate ◽  
Tunneling Microscopy ◽  
Elastic Band ◽  
Lennard Jones

<p>A Kinetic Monte Carlo (KMC) method was developed to model homoepitaxy and grain boundary propagation on a (111) surface. Barrier energies were calculated using the Nudged Elastic Band (NEB) technique. A recently reported inertial relaxation technique named FIRE (the Fast Inertial Relaxation Engine) was used to relax the NEB images. Both the Lennard-Jones potential and a Sutton-Chen Iridium potential were used and compared. A doubly-refined lattice mesh was developed to incorporate atoms in Face-Centred-Cubic (FCC) and Hexagonal-Close-Packed (HCP) sites as well as atoms in decorated row sites (i.e. supported by 4 atoms). A look-up table was developed to identify hops in the KMC algorithm. The KMC results show that a small difference in energy barriers between FCC and HCP sites on the substrate can cause a substantial bias in the direction of grain boundary propagation. We also investigated the effect of the geometry of the grain boundary on its propagation, as well as the atomistic processes involved in grain boundary propagation and the merger of grain boundaries. Our deposition simulations produced islands with loosely triangular envelopes, where FCC islands are rotated 180° with respect to HCP islands. The results are similar to scanning tunneling microscopy (STM) images of Iridium deposition, although lack of computing power forced us to use a high deposition rate and this caused some differences.</p>

MODELING OF CO-DEPOSITION OF INDIUM AND TIN ON SILICON(100): A KINETIC MONTE CARLO STUDY

2011 ◽  
Vol 25 (14) ◽  
pp. 1889-1898 ◽  
Author(s):  
DARWIN B. PUTUNGAN ◽  
HENRY J. RAMOS ◽  
FENG-CHUAN CHUANG ◽  
MARVIN A. ALBAO
Keyword(s):  
Monte Carlo ◽  
Room Temperature ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Study ◽  
Scanning Tunneling ◽  
Flux Rate ◽  
Tunneling Microscopy ◽  
Apparent Lack ◽  
Chemical Selectivity ◽  
Shed Light

A growth model for co-deposition of Sn and In on Si (100) at room-temperature was simulated using Kinetic Monte Carlo methods to shed light on the chemical selectivity and lack of dimer ordering seen in [Jure et al., Appl. Surf. Sci.162, 638 (2000)], a Scanning Tunneling Microscopy (STM) study. In this work, the experimental observation that the number of mixed In – Sn dimers is unaffected even when the relative flux rates are adjusted to favor In over Sn (by 100:1) — a manifestation of some sort of chemical selectivity — was investigated. Our simulations reveal that this phenomenon is ultimately related to the fact that the number of Sn -terminated chains is largely unaffected by the relative flux rate. Finally, we found that the attraction between metal dimers (whether of the same or different species) within a Si dimer row has only negligible effect on the apparent lack of dimer ordering seen in the STM study. Instead, dimer ordering is controlled by the detachment barriers in dimer-terminated islands.

Rapid adatom island decay on Cu(111): a kinetic Monte Carlo simulation study

2001 ◽  
Vol 672 ◽  
Author(s):  
Mats I. Larsson
Keyword(s):  
Monte Carlo ◽  
Nearest Neighbor ◽  
Kinetic Monte Carlo ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Monte Carlo Simulation Study ◽  
One Dimensional ◽  
Edge Crossing ◽  
The One ◽  
Counting Model

ABSTRACTKinetic Monte Carlo (KMC) simulations are used to investigate the recent scanning tunneling microscopy (STM) measurements of fast decaying adatom islands on Cu(111). The KMC model is a full diffusion bond-counting model including nearest neighbor as well as second-nearest neighbor interactions. For encounters between steps in adjacent atomic layers of an island it is demonstrated that a moderately reduced activation energy for interlayer adatom transport is enough to obtain correspondence between simulations and experiments, provided that the one-dimensional Ehrlich-Schwoebel barrier for corner transitions is reduced to zero. The results presented in this report are interesting because they demonstrate that step-edge crossing by simple adatom hopping is sufficient to explain the rapid island-decay mechanism.

Combined DFT and kinetic Monte Carlo study of a bridging-spillover mechanism on fluorine-decorating graphene

2020 ◽  
Author(s):  
Jing-hua Guo ◽  
Jin-Xiang Liu ◽  
Hongbo Wang ◽  
Haiying Liu ◽  
Gang Chen
Keyword(s):  
Monte Carlo ◽  
First Principles ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Study ◽  
First Principles Calculations ◽  
Graphene Surface

In this work, combining the first-principles calculations with kinetic Monte Carlo (KMC) simulations, we constructed an irregular carbon bridge on the graphene surface and explored the process of H migration...

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