Island Size and Environment Dependence of Adatom Capture: Cu/Co Islands on Ru(0001)

1998 ◽  
Vol 528 ◽  
Author(s):  
M.C. Bartelt ◽  
J.W. Evans ◽  
A.K. Schmid ◽  
R.Q. Hwang
Keyword(s):  
Kinetic Monte Carlo ◽  
Strong Dependence ◽  
Mean Field ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Island Size ◽  
Kinetic Monte Carlo Simulations ◽  
Environment Dependence ◽  
And Diffusion ◽  
Capture Rates

AbstractThe rate of capture by stable Co islands on Ru(0001) of additionally deposited Cu atoms is quantified using scanning tunneling microscopy, kinetic Monte Carlo simulations, and diffusion equation analyses. We find strong dependence of the capture rates on Co-island size, larger islands showing larger capture rates, qualitatively distinct from self-consistent mean-field predictions. The observed size dependence is shown to reflect larger island-free areas surrounding bigger islands, i.e., a strong correlation between island sizes and separations neglected in mean-field treatments.

Ripening Mechanisms in Ultrathin Metal Films

1998 ◽  
Vol 528 ◽  
Author(s):  
Georg Rosenfeld ◽  
Marcus Essera ◽  
Karina Morgensternat ◽  
George Comsa
Keyword(s):  
Ostwald Ripening ◽  
Mean Field ◽  
Metal Films ◽  
Binary Collision ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Island Size ◽  
Model Studies ◽  
Ultrathin Metal Films ◽  
Local Correlations

AbstractResults of recent experimental model studies on ripening of submonolayer films via Ostwald ripening and dynamic coalescence are described. The experiments have been performed on ensembles of Ag-adatom or vacancy islands on a Ag(111) surface using Scanning Tunneling Microscopy. For Ostwald ripening of adatom islands, deviations from the classical mean-field ripening behaviour are observed which show up as pronounced local correlations in island decay and growth rates. For ripening via dynamic coalescence which is studied for ensembles of vacancy islands, it is found that the increase of the average island size with time in the late-stage regime is correctly described by the classical binary collision model.

scholarly journals Crossover from Dimer Nucleation to Adatom Exchange During Submonolayer Epitaxy

1995 ◽  
Vol 399 ◽  
Author(s):  
G.S. Bales
Keyword(s):  
Kinetic Monte Carlo ◽  
Mean Field ◽  
Nucleation And Growth ◽  
Rate Equations ◽  
Number Density ◽  
Dimer Formation ◽  
Island Size ◽  
Self Consistent ◽  
Kinetic Monte Carlo Simulations ◽  
Increasing Temperature

ABSTRACTThe nucleation and growth of islands in the early stages of epitaxial growth is studied with kinetic Monte Carlo Simulations and self-consistent mean field rate equations. Specifically, adatom exchange and irreversible dimer formation are allowed to compete equally as the origin of two-dimensional islands. The island size distribution and number density are found to satisfy a dynamic crossover scaling form. The critical island size evolves from one to zero with increasing temperature, decreasing flux, and increasing coverage.

Vacancy-Mediated Diffusion and Diffusion-Controlled Processes in Ordered Binary Intermetallics by Kinetic Monte Carlo Simulations

2021 ◽  
Vol 29 ◽  
pp. 95-115
Author(s):  
Rafal Kozubski ◽  
Graeme E. Murch ◽  
Irina V. Belova
Keyword(s):  
Monte Carlo ◽  
Kinetic Monte Carlo ◽  
Simulation Studies ◽  
Self Diffusion ◽  
Monte Carlo Techniques ◽  
Diffusion Controlled ◽  
Kinetic Monte Carlo Simulations ◽  
Kinetic Effects ◽  
Kinetics Of ◽  
And Diffusion

We review the results of our Monte Carlo simulation studies carried out within the past two decades in the area of atomic-migration-controlled phenomena in intermetallic compounds. The review aims at showing the high potential of Monte Carlo methods in modelling both the equilibrium states of the systems and the kinetics of the running processes. We focus on three particular problems: (i) the atomistic origin of the complexity of the ‘order-order’ relaxations in γ’-Ni3Al; (ii) surface-induced ordering phenomena in γ-FePt and (iii) ‘order—order’ kinetics and self-diffusion in the ‘triple-defect’ β-NiAl. The latter investigation demonstrated how diverse Monte Carlo techniques may be used to model the phenomena where equilibrium thermodynamics interplays and competes with kinetic effects.

scholarly journals Step bunching during Si(001) homoepitaxy caused by the surface diffusion anisotropy

2002 ◽  
Vol 749 ◽  
Author(s):  
J. Mysliveček ◽  
C. Schelling ◽  
F. Schäffler ◽  
G. Springholz ◽  
P. Šmilauer ◽  
...  
Keyword(s):  
Kinetic Monte Carlo ◽  
Monte Carlo Model ◽  
Growth Conditions ◽  
Scanning Tunneling ◽  
Diffusion Anisotropy ◽  
Island Growth ◽  
Tunneling Microscopy ◽  
Step Bunching ◽  
Step Flow ◽  
Step Flow Growth

ABSTRACTScanning tunneling microscopy experiments show that the unstable growth morphology observed during molecular beam homoepitaxy on slightly vicinal Si(001) surfaces consists of straight step bunches. The instability occurs under step-flow growth conditions and vanishes both during low-temperature island growth and at high temperatures. An instability with the same characteristics is observed in a 2D Kinetic Monte Carlo model of growth with incorporated Si(001)-like diffusion anisotropy. This provides strong evidence that the diffusion anisotropy destabilizes growth on Si(001) and similar surfaces towards step bunching. This new instability mechanism is operational without any additional step edge barriers.

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