scholarly journals Impact of Surface Roughness on Crystal Nucleation

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Patrick Grosfils ◽  
James F. Lutsko
Keyword(s):  
Nucleation Rate ◽  
Rough Surfaces ◽  
Kinetic Monte Carlo ◽  
Three Dimensional ◽  
Crystal Nucleation ◽  
Bulk Solution ◽  
And Topology ◽  
Kinetic Monte Carlo Simulations ◽  
Small Clusters ◽  
Local Supersaturation

We examine the effect of rough surfaces on crystal nucleation by means of kinetic Monte Carlo simulations. Our work makes use of three-dimensional kMC models, explicit representation of transport in solution and rough surfaces modeled as randomly varying height fluctuations (roughness) with exponentially decaying correlation length (topology). We use Forward-Flux Sampling to determine the nucleation rate for crystallization for surfaces of different roughness and topology and show that the effect on crystallization is a complex interplay between the two. For surfaces with low roughness, small clusters form on the surface but as clusters become larger they are increasingly likely to be found in the bulk solution while rougher surfaces eventually favor heterogeneous nucleation on the surface. In both cases, the rough surface raises the local supersaturation in the solution thus leading to another mechanism of enhanced nucleation rate.

Monte Carlo Study of the Hetero-Polytypical Growth of Cubic on Hexagonal Silicon Carbide Polytypes

2013 ◽  
Vol 740-742 ◽  
pp. 295-300 ◽  
Author(s):  
Massimo Camarda ◽  
Antonino La Magna ◽  
Francesco La Via
Keyword(s):  
Silicon Carbide ◽  
Monte Carlo ◽  
Epitaxial Film ◽  
Kinetic Monte Carlo ◽  
Three Dimensional ◽  
Monte Carlo Study ◽  
Kinetic Monte Carlo Simulations ◽  
Cubic Silicon Carbide ◽  
Silicon Carbide Polytype

We use three dimensional kinetic Monte Carlo simulations on super-lattices to study the hetero-polytypical growth of cubic silicon carbide polytype (3C-SiC) on misoriented hexagonal (4H and 6H) substrates finding that the growth on misoriented (4°-10° degree off) 6H substrates, with step bunched surfaces, can strongly improve the quality of the cubic epitaxial film promoting 3C single domain growths

Monte Carlo Study of the early Growth Stages of 3C-SiC on Misoriented <11-20> and <1-100> 6H-SiC Substrates: Role of Step-Island Interaction

2015 ◽  
Vol 821-823 ◽  
pp. 201-204
Author(s):  
Massimo Camarda ◽  
Antonino La Magna ◽  
Francesco La Via
Keyword(s):  
Monte Carlo ◽  
Kinetic Monte Carlo ◽  
Three Dimensional ◽  
Monte Carlo Study ◽  
Growth Stages ◽  
Specific Direction ◽  
Kinetic Monte Carlo Simulations ◽  
Cubic Silicon Carbide ◽  
Silicon Carbide Polytype

In this paper we use three dimensional kinetic Monte Carlo simulations on super-lattices to study the hetero-polytypical growth of cubic silicon carbide polytype (3C-SiC) on hexagonal 6H-SiC step-bunched substrates with miscuts towards the <11-20> and <1-100> directions. We find that the preferential 3C conversion observed on <1-100> misoriented substrates could be due to a different step-to-island interaction which enhances island stability and expansion in this specific direction. For this reason 3-4° degrees off step-bunched 6H substrates with miscut towards the <1-100> direction should be the best choice for the stable and reproducible hetero-polytypical growth of high quality cubic epitaxial films.

scholarly journals From time dependent incorporation of molecular building blocks to application properties for inorganic and organic three-dimensional network polymers

2020 ◽  
Author(s):  
Lies De Keer ◽  
Karsu Kilic ◽  
Paul Van Steenberge ◽  
Lode Daelemans ◽  
Daniel Kodura ◽  
...  
Keyword(s):  
Structural Information ◽  
Kinetic Monte Carlo ◽  
Chemical Reactivity ◽  
Three Dimensional ◽  
Building Blocks ◽  
Structure Property ◽  
Dynamic Simulations ◽  
Application Range ◽  
Molecular Building Blocks ◽  
Kinetic Monte Carlo Simulations

Abstract The three-dimensional configurational arrangement of natural and synthetic network materials determines their application range. Control of the real time incorporation of each building block, hence, all functional groups is desired so that we can regulate macroscopic properties from the molecular level onwards. Here we interconnect kinetic Monte Carlo simulations from the field of chemical kinetics and molecular dynamic simulations from the field of physics. We visualize for (in)organic network material synthesis how the initial building blocks interact timewise and spatially, accounting for variations in inter- and intramolecular chemical reactivity, diffusivity, segmental compositions, branch/network point locations, and defects. We use the kinetic and three-dimensional structural information to construct structure-property relationships based on molecular descriptors such as the molecular pore size or dangling chain distribution, differentiating between ideal and non-ideal structural elements. The generic nature is illustrated by constructing such relationships for the synthesis of organosilica, epoxy-amine and Diels-Alder based networks.

Evolution of Stacking Faults Defects During Epitaxial Growths: Role of Surface Kinetics

2010 ◽  
Vol 1246 ◽  
Author(s):  
Massimo Camarda ◽  
Antonino La Magna ◽  
Andrea Canino ◽  
Francesco La Via
Keyword(s):  
Kinetic Monte Carlo ◽  
Three Dimensional ◽  
Stacking Faults ◽  
Perfect Crystal ◽  
Dislocation Loops ◽  
Surface Kinetics ◽  
Local Growth ◽  
Kinetic Monte Carlo Simulations ◽  
Deposition Conditions

AbstractThree dimensional kinetic Monte Carlo simulations on super-lattices are applied to study the evolution of stacking faults during epitaxial growths. We show that, in the case of misoriented close packed substrates, these defects can either extend throughout the entire epilayer (i.e. extended from the substrate up to the surface) or close in dislocation loops, in dependence of the deposition conditions. We explain this behavior in terms of a surface kinetic competition between these defects and the surrounding crystal: if the local growth rate of the defect is larger compared with that of the perfect crystal the defect will expands, otherwise it will closes. This mechanisms allows to explain several experimental results on homo and hetero epitaxies.

Kinetic Monte Carlo simulations of three-dimensional self-assembled quantum dot islands

2014 ◽  
Vol 23 (1) ◽  
pp. 016802
Author(s):  
Xin Song ◽  
Hao Feng ◽  
Yu-Min Liu ◽  
Zhong-Yuan Yu ◽  
Hao-Zhi Yin
Keyword(s):  
Monte Carlo ◽  
Quantum Dot ◽  
Monte Carlo Simulations ◽  
Kinetic Monte Carlo ◽  
Three Dimensional ◽  
Kinetic Monte Carlo Simulations ◽  
Self Assembled

A 3-D Kinetic Monte Carlo Study of the Growth of Si Thin Films Using Beams With Varying Angle of Incidence

1996 ◽  
Vol 440 ◽  
Author(s):  
S.W. Levine ◽  
J.R. Engstrom ◽  
P. Clancy
Keyword(s):  
Monte Carlo ◽  
Kinetic Monte Carlo ◽  
Three Dimensional ◽  
Incident Beam ◽  
Monte Carlo Study ◽  
Columnar Structure ◽  
Layer Growth ◽  
Angle Of Incidence ◽  
Kinetic Monte Carlo Simulations ◽  
Porous Thin Film

AbstractThree-dimensional Kinetic Monte Carlo simulations were used to model the deposition of a hyperthermal molecular beam at varying angles of incidence. The simulations incorporate incident atom-substrate interactions, many layer growth, and attempt to mimic deposition and growth of Si on a Si(100) substrate. At high angles of incidence, the formation of “flake”-like structures are seen. The growth of the flakes follow the same general trends as previous two-dimensional simulations where non-local shadowing produces a porous thin film and the columns grow into the incident beam. Increased substrate temperature increased the widths of the flakes perpendicular to the path of the beam and allowed the grown film to remain defect-free for a time before columnar structure begins.

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