Exact Scaling Form for the Island Size Distribution in Submonolayer Epitaxial Growth

1996 ◽  
Vol 440 ◽  
Author(s):  
M. C. Bartelt ◽  
J. W. Evans
Keyword(s):  
Epitaxial Growth ◽  
Size Distribution ◽  
Nucleation And Growth ◽  
Complex Relationship ◽  
Island Size ◽  
The Relationship ◽  
Exact Scaling

AbstractThe exact scaling form is determined for the size distribution of islands created via irreversible nucleation and growth during submonolayer deposition. This form is controlled by a dependence on size of the propensity for islands to “capture” diffusing adatoms. This sizedependence is determined directly from simulations. It reflects a complex relationship between the size of an island, and the area of its cell in a tessellation of the surface based on the island locations. The relationship corresponds to a correlation between island size and separation.

Irreversible Island Formation During Deposition: Island Size and Separation Distributions

1992 ◽  
Vol 280 ◽  
Author(s):  
M. C. Bartelt ◽  
M. C. Tringides ◽  
J. W. Evans
Keyword(s):  
Size Distribution ◽  
Rate Equation ◽  
Nucleation And Growth ◽  
Simplified Model ◽  
Island Size ◽  
Deposition Rates ◽  
Island Formation ◽  
Simulation Results ◽  
Precise Simulation

ABSTRACTWe present precise simulation results for a simplified model of irreversible nucleation and growth of islands during deposition. We characterize the scaling of the island and adatom densities, the complete island size distribution, and the adatom-island and island-island separation distributions, with the ratio of diffusion to deposition rates (for fixed coverages,θ<1). We also make some comparisons with rate equation predictions.

Germanium Island Size Distribution by Atomistic Simulation

2003 ◽  
Vol 794 ◽  
Author(s):  
Richard J. Wagner ◽  
Erdogan Gulari
Keyword(s):  
Quantum Dots ◽  
Epitaxial Growth ◽  
Size Distribution ◽  
Atomistic Simulation ◽  
Chemical Potential ◽  
Gibbs Distribution ◽  
Nanometer Scale ◽  
Size Distributions ◽  
Island Size ◽  
Self Assembled

ABSTRACTStrained epitaxial growth of Ge on Si(001) produces self-assembled, nanometer scale islands, or quantum dots. We study this growth by atomistic simulation, computing the energy of island structures to determine when and how islanding occurs. The distribution of island sizes on a surface is determined by the relation of island energy to size. Applying the calculated chemical potential to the Boltzmann-Gibbs distribution, we predict size distributions as functions of coverage and temperature. The peak populations around 80 000 atoms (35 nm wide) compare favorably with experiment.

Critical Cluster Size: Island Morphology and Size Distribution in Submonolayer Epitaxial Growth

1994 ◽  
Vol 367 ◽  
Author(s):  
Jacques G. Amar ◽  
Fereydoon Family
Keyword(s):  
Epitaxial Growth ◽  
Size Distribution ◽  
Excellent Agreement ◽  
Bond Activation ◽  
Kinetic Monte Carlo ◽  
Analytic Form ◽  
Analytical Form ◽  
Island Size ◽  
Kinetic Monte Carlo Simulations ◽  
The One

AbstractThe island-size distribution scaling function fi (u) corresponding to submonolayer epitaxial growth with critical island size i is studied via kinetic Monte Carlo simulations for i = 0, 1, 2, and 3. An analytic form for fi (u) based on a conjecture for the small-u behavior is also presented. For i = 1, the scaled island-size distribution is found to depend on island morphology. In particular, for fractal islands with i = 1 there is excellent agreement with our analytical form as well as with experiments on low temperature Fe/Fe(100) deposition. However, for compact islands with i = 1, the scaled distribution is found to deviate slightly at small u. We also find excellent agreement between our analytical form, simulations, and experiment for i =- 2 and i = 3. Good agreement between our simulation results for i = 0 and recent experiments on Fe/Cu(100) deposition is also found. Results for the scaling of the island-density as well as crossover scaling forms for the transition from i = 1 to i = 2 and from i = 1 to i = 3 are also presented and used to determine the one-bond activation energy and critical island size transition temperature for Fe/Fe(100). The morphology of fractal islands for i = 2 is also studied and compared with experiments on Au/Ru(0001).

scholarly journals A new method for calculation of island-size distribution in submonolayer epitaxial growth

2011 ◽  
Vol 35 (3) ◽  
pp. 1331-1336 ◽  
Author(s):  
P.P. Petrov ◽  
W. Miller ◽  
U. Rehse ◽  
R. Fornari
Keyword(s):  
Epitaxial Growth ◽  
Size Distribution ◽  
New Method ◽  
Island Size

PHENOMENOLOGICAL VIEW OF NUCLEATION AND GROWTH OF Si ON THE Si(111)-(7×7) SUPERLATTICE

2000 ◽  
Vol 07 (01n02) ◽  
pp. 61-66 ◽  
Author(s):  
YUKICHI SHIGETA
Keyword(s):  
Activation Energy ◽  
Free Energy ◽  
Surface Structure ◽  
Epitaxial Growth ◽  
Size Distribution ◽  
Nucleation And Growth ◽  
Island Growth ◽  
Rearrangement Process ◽  
Phenomenological Consideration ◽  
The Difference

The influence of surface structure on epitaxial growth, which has not been considered before in the crystal growth theory, is discussed for the case of epitaxial growth of Si on Si(111)-(7×7) substrate. Since the rearrangement of surface structure is essential for progressing the epitaxial growth, the activation energy for the rearrangement is considered into the free energy change in the nucleation and growth processes. From a phenomenological consideration, some features of island shape and size distribution, which had been observed, are clearly explained. The size distribution is discontinuous according to the size of the unit cell of the superlattice and the shape will be almost triangular. These features are caused by prevention of the lateral growth at the faulted half in the 7×7 structure. After the evaporation has been stopped, the detachment of atoms from corners of the triangular island starts and the island shows a rounded shape. The detachment after the deposition is also explained by the difference in the free energy changes between during and after deposition. It is suggested that the activation energy for the rearrangement process of the 7×7 structure with island growth is much higher than that for the formation process with thermal decay of the Si island.

scholarly journals Does Tenure Security Reduce Disaster Risk? A Comparative Study of the Nairobi Settlements of Kibera and Kawangware

2021 ◽  
Author(s):  
Rónán McDermott ◽  
Pat Gibbons ◽  
Dalmas Ochieng ◽  
Charles Owuor Olungah ◽  
Desire Mpanje
Keyword(s):  
Structural Integrity ◽  
Disaster Risk ◽  
Comparative Case Study ◽  
Complex Relationship ◽  
Tenure Security ◽  
Household Level ◽  
Urban Informal Settlements ◽  
The Relationship

AbstractWhile scholarship suggests that improving tenure security and housing significantly reduces disaster risk at the household level within urban settings, this assertion has not been adequately tested. Tenure security can be conceived as being composed of three interrelated and overlapping forms: tenure security as determined by legal systems; de facto tenure security; and tenure security as perceived by residents. This article traces the relationship between tenure security, the quality of housing, and disaster risk on the basis of a mixed methods comparative case study of the settlements of Kawangware and Kibera in Nairobi. Although the findings suggest that owner-occupancy is associated with the structural integrity of dwellings to a greater extent than tenantship, no association was found between the length of occupancy by households and the structural integrity of the dwelling. Moreover, tenantship is not found to be closely associated with fires and flooding affecting the dwelling as extant scholarship would suggest. Formal ownership is linked with greater investment and upgrading of property with significant implications for disaster risk. Our findings highlight the complex relationship between tenure security and disaster risk in urban informal settlements and provide impetus for further investigation.

scholarly journals What Is the Relationship between the Presence of Volatile Organic Compounds in Food and Drink Products and Multisensory Flavour Perception?

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1570
Author(s):  
Charles Spence
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mass Spectrometry Data ◽  
Complex Relationship ◽  
Chemical Profile ◽  
Volatile Organic ◽  
Flavour Perception ◽  
Food And Drink ◽  
The Relationship ◽  
Unique Chemical

This narrative review examines the complex relationship that exists between the presence of specific configurations of volatile organic compounds (VOCs) in food and drink products and multisensory flavour perception. Advances in gas chromatography technology and mass spectrometry data analysis mean that it is easier than ever before to identify the unique chemical profile of a particular food or beverage item. Importantly, however, there is simply no one-to-one mapping between the presence of specific VOCs and the flavours that are perceived by the consumer. While the profile of VOCs in a particular product undoubtedly does tightly constrain the space of possible flavour experiences that a taster is likely to have, the gustatory and trigeminal components (i.e., sapid elements) in foods and beverages can also play a significant role in determining the actual flavour experience. Genetic differences add further variation to the range of multisensory flavour experiences that may be elicited by a given configuration of VOCs, while an individual’s prior tasting history has been shown to determine congruency relations (between olfaction and gustation) that, in turn, modulate the degree of oral referral, and ultimately flavour pleasantness, in the case of familiar foods and beverages.

scholarly journals Particle Size Distribution Based Occurrence Features of Organic Components in Printing and Dyeing Wastewater Under a Treatment Process

2019 ◽  
Vol 118 ◽  
pp. 04009
Author(s):  
Yuan Li ◽  
Jie Liu ◽  
Yibiao Yu ◽  
Hao Zhu ◽  
Zheng Shen ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Reverse Osmosis ◽  
Treatment Process ◽  
Dyeing Wastewater ◽  
Wastewater Treatment Process ◽  
Printing And Dyeing Wastewater ◽  
Sedimentation Tank ◽  
The Relationship

A more detailed occurrence features of organic matters in the printing and dyeing wastewater, based on its particle size distribution (PSD) and along with a wastewater treatment process, was conducted to provide a support for advanced treatment. Results suggested that, (1) In the dyeing wastewater, the occurrence characteristic of COD was: soluble>supra colloidal>colloidal>settleable; However, for protein, the supra colloidal was dominant, followed by the soluble. The feature of the polysaccharide was consistent with COD’s. In the wastewater, 29.66% of COD could be attributed to proteins and 3.45% of the COD could be attributed to polysaccharides. (2) The relationship among the forms of COD in the primary sedimentation tank, aerobic tank, secondary sedimentation tank, and reverse osmosis-treated concentrated effluent was consistent, that was: soluble>colloidal>supra colloidal>settleable. (3) In the primary sedimentation tank, the settleable COD was almost completely removed; In the aerobic tank, the residual super colloidal COD was not much; After MBR-RO treatment, the COD in the reverse osmosis concentrated water was almost dissolved and only a little presented in other forms.

Evolution of cluster size distribution in nucleation and growth processes

1991 ◽  
Vol 136 (3) ◽  
pp. 181-197 ◽  
Author(s):  
J. Bartels ◽  
U. Lembke ◽  
R. Pascova ◽  
J. Schmelzer ◽  
I. Gutzow
Keyword(s):  
Size Distribution ◽  
Cluster Size ◽  
Nucleation And Growth ◽  
Cluster Size Distribution ◽  
Growth Processes
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