Thermodynamic analysis of Al clusters formation over aluminum melt

2021 ◽  
Author(s):  
Alexey Zhokh ◽  
Peter Strizhak ◽  
Maksym Goryuk ◽  
Anatolii Narivskiy
Keyword(s):  
Size Distribution ◽  
Gas Phase ◽  
Thermodynamic Analysis ◽  
Thermodynamic Modeling ◽  
Cluster Size ◽  
Magic Numbers ◽  
Aluminum Nanoparticles ◽  
Aluminum Melt ◽  
Synthesis Conditions ◽  
Equilibrium Shift

Abstract The formation of the aluminum nanoparticles with the size of up to 60 atoms in a gas phase is theoretically studied. Thermodynamic modeling has been applied to investigate the effect of the synthesis conditions on the distribution of the nanoparticles. The magic numbers of the particles have been estimated and found to be consistent with the available data. Furthermore, the simulations showed that higher amounts of larger nanoparticles are obtained during condensation from the supercooled aluminum vapor. In contrast, lower amounts of smaller clusters may be formed in a gas phase over the aluminum melt. Varying the temperature and concentration of supercooled aluminum vapor in a broad range results in no significant change in cluster size distribution. This effect is governed by the equilibrium shift.

Magic Numbers for Bimetallic Clusters

2011 ◽  
Vol 172-174 ◽  
pp. 1038-1043 ◽  
Author(s):  
Isabelle Braems ◽  
Fabienne Berthier
Keyword(s):  
Size Distribution ◽  
Ground State ◽  
Cluster Size ◽  
Cluster Size Distribution ◽  
Bimetallic Clusters ◽  
Magic Numbers ◽  
Chemical Interactions ◽  
Two Component ◽  
Component Phase ◽  
Exact Description

An exact description of the distribution of 2D bimetallic clusters deposited on a square substrate has been obtained via an exact inventory algorithm. We show that several features of the monometallic distribution can be altered by the presence of a second species within the clusters. The diagram of ground-state morphologies of such clusters is built as a function of the chemical interactions between both components. As a consequence, the maxima in the cluster size distribution that indicate the magic numbers can be smoothened or shifted during co-deposition as a function of the composition of the two-component phase.

scholarly journals Nucleation of Ga droplets self-assembly on GaAs(111)A substrates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Artur Tuktamyshev ◽  
Alexey Fedorov ◽  
Sergio Bietti ◽  
Stefano Vichi ◽  
Riccardo Tambone ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Size Distribution ◽  
Self Assembly ◽  
Cluster Size ◽  
Droplet Size Distribution ◽  
Local Environment ◽  
The Self ◽  
Critical Cluster ◽  
Droplet Nucleation ◽  
High Degree

AbstractWe investigated the nucleation of Ga droplets on singular GaAs(111)A substrates in the view of their use as the seeds for the self-assembled droplet epitaxial quantum dots. A small critical cluster size of 1–2 atoms characterizes the droplet nucleation. Low values of the Hopkins-Skellam index (as low as 0.35) demonstrate a high degree of a spatial order of the droplet ensemble. Around $$350\,^{\circ }\hbox {C}$$ 350 ∘ C the droplet size distribution becomes bimodal. We attribute this observation to the interplay between the local environment and the limitation to the adatom surface diffusion introduced by the Ehrlich–Schwöbel barrier at the terrace edges.

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

Synthesis of Sic Fine Particles by Gas-Phase Reaction Under Short-Time Microgravity

1992 ◽  
Vol 286 ◽  
Author(s):  
Takeshi Okutani ◽  
Yoshinori Nakata ◽  
Masaakt Suzuki ◽  
Yves Maniette ◽  
Nobuyoshi Goto ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Heat Source ◽  
Size Distribution ◽  
Gas Phase ◽  
Fine Particles ◽  
Rapid Heating ◽  
Exothermic Reaction ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Short Time

ABSTRACTSiC fine particles were synthesized by the gas-phase thermal decomposition of tetramethylsilane (Si(CH3)4) in hydrogen under microgravity of 10−4G for 10 sec. Rapid heating to the temperature over 800°C which is required for thermal decomposition of Si(CH3)4) under short-time microgravity was attained using a chemical oven where the heat of exothermic reaction of combustion synthesis of Ti-A1-4B composites was used as the heat source. Monodisperse and spherical SiC fine particles were synthesized under microgravity, whereas aggregates of SiC fine particles were synthesized under 1 G gravity. The SiC particles synthesized under microgravity (150-200 nm) were bigger in size and narrower in size distribution than those under 1 G gravity (100-150 nm).

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