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Wang WB, Ohta R, Kambara M. Study on liquid-like SiGe cluster growth during co-condensation from supersaturated vapor mixtures by molecular dynamics simulation. Phys Chem Chem Phys 2022; 24:7442-7450. [PMID: 35274111 DOI: 10.1039/d1cp05589e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Based on the co-condensation processes in the Si-Ge system upon cooling, as determined by molecular dynamics (MD) simulation, we explored the mixed cluster growth dynamics and structural properties leading to the synthesis of liquid-like SiGe nanoclusters. The results indicated that the cluster size quickly increased to large clusters by the coalescence of transient small clusters in the growth stage during co-condensation. The transient clusters at different temperatures were verified to have slightly Si-rich compositions and liquid-like structures. The coalescence of such nanoclusters at high temperatures led to spherical clusters with homogeneous intermixing. However, irregularly shaped clusters with attached mixed parts were obtained owing to incomplete coalescence at low temperatures. Ge atoms tended to move to the cluster surface to exploit their energetically favorable state during the restructuring process, leading to slightly Ge-rich components on the cluster surface. The degree of intermixing for SiGe nanoclusters was related to cluster size. Generally, small clusters appeared to be more segregated during restructuring.
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Affiliation(s)
- Wen-Bo Wang
- Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-0033, Japan.
| | - Ryoshi Ohta
- Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-0033, Japan.
| | - Makoto Kambara
- Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-0033, Japan.
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Förster GD, Benoit M, Lam J. Alloy, Janus and core-shell nanoparticles: numerical modeling of their nucleation and growth in physical synthesis. Phys Chem Chem Phys 2019; 21:22774-22781. [PMID: 31595276 DOI: 10.1039/c9cp04231h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
While alloy, core-shell and Janus binary nanoclusters are found in more and more technological applications, their formation mechanisms are still poorly understood, especially during synthesis methods involving physical approaches. In this work, we employ a very simple model of such complex systems using Lennard-Jones interactions and inert gas quenching. After demonstrating the ability of the model to well reproduce the formation of alloy, core-shell or Janus nanoparticles, we studied their temporal evolution from the gas via droplets to nanocrystalline particles. In particular, we showed that the growth mechanisms exhibit qualitative differences between these three chemical orderings. Then, we determined how the quenching rate can be used to finely tune structural characteristics of the final nanoparticles, including size, shape and crystallinity.
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Affiliation(s)
- Georg Daniel Förster
- Laboratoire d'Étude des Microstructures, ONERA-CNRS, UMR104, Université Paris-Saclay, BP 72, 92322 Châtillon Cedex, France
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Abbaspour M, Valizadeh Z, Jorabchi MN. Nucleation, coalescence, thermal evolution, and statistical probability of formation of Au/Ir/Pd nanoalloys in gas-phase condensation process. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.10.152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abbaspour M, Akbarzadeh H, Salemi S, Lotfi S. Investigation of Possible Formation of Au@M (M = Cu, Ir, Pt, and Rh) Core–Shell Nanoclusters in a Condensation–Coalescence Process Using Molecular Dynamics Simulations. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b03724] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Mohsen Abbaspour
- Department of Chemistry, Hakim Sabzevari University, 96179-76487 Sabzevar, Iran
| | - Hamed Akbarzadeh
- Department of Chemistry, Hakim Sabzevari University, 96179-76487 Sabzevar, Iran
| | - Sirous Salemi
- Department of Chemistry, Hakim Sabzevari University, 96179-76487 Sabzevar, Iran
| | - Samira Lotfi
- Department of Chemistry, Hakim Sabzevari University, 96179-76487 Sabzevar, Iran
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Ghorai S, Chaudhury P. Predicting stability limits for pure and doped dicationic noble gas clusters undergoing coulomb explosion: A parallel tempering based study. J Comput Chem 2018; 39:827-838. [PMID: 29282763 DOI: 10.1002/jcc.25156] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 12/07/2017] [Accepted: 12/12/2017] [Indexed: 11/10/2022]
Abstract
We have used a replica exchange Monte-Carlo procedure, popularly known as Parallel Tempering, to study the problem of Coulomb explosion in homogeneous Ar and Xe dicationic clusters as well as mixed Ar-Xe dicationic clusters of varying sizes with different degrees of relative composition. All the clusters studied have two units of positive charges. The simulations reveal that in all the cases there is a cutoff size below which the clusters fragment. It is seen that for the case of pure Ar, the value is around 95 while that for Xe it is 55. For the mixed clusters with increasing Xe content, the cutoff limit for suppression of Coulomb explosion gradually decreases from 95 for a pure Ar to 55 for a pure Xe cluster. The hallmark of this study is this smooth progression. All the clusters are simulated using the reliable potential energy surface developed by Gay and Berne (Gay and Berne, Phys. Rev. Lett. 1982, 49, 194). For the hetero clusters, we have also discussed two different ways of charge distribution, that is one in which both positive charges are on two Xe atoms and the other where the two charges are at a Xe atom and at an Ar atom. The fragmentation patterns observed by us are such that single ionic ejections are the favored dissociating pattern. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Sankar Ghorai
- Department of Chemistry, University of Calcutta, 92 A P C Road, Kolkata, 700 009, India
| | - Pinaki Chaudhury
- Department of Chemistry, University of Calcutta, 92 A P C Road, Kolkata, 700 009, India
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Abbaspour M, Akbarzadeh H, Valizadeh Z. Au–Ir nanoalloy nucleation during the gas-phase condensation: a comprehensive MD study including different effects. Inorg Chem Front 2018. [DOI: 10.1039/c8qi00177d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The number of formed clusters and their size increases with the increasing temperature and pressure, which is in good agreement with the experimental results.
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Affiliation(s)
- Mohsen Abbaspour
- Department of Chemistry
- Faculty of Basic Sciences
- Hakim Sabzevari University
- 96179-76487 Sabzevar
- Iran
| | - Hamed Akbarzadeh
- Department of Chemistry
- Faculty of Basic Sciences
- Hakim Sabzevari University
- 96179-76487 Sabzevar
- Iran
| | - Zahra Valizadeh
- Department of Chemistry
- Faculty of Basic Sciences
- Hakim Sabzevari University
- 96179-76487 Sabzevar
- Iran
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Akbarzadeh H, Abbaspour M, Mehrjouei E, Masoumi A. Structural evolution of Pt/Pd nanoparticles in condensation process. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.10.132] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Talukder S, Sen S, Neogi SG, Chaudhury P. A parallel tempering based study of Coulombic explosion and identification of dissociating fragments in charged noble gas clusters. J Chem Phys 2013; 139:164312. [PMID: 24182034 DOI: 10.1063/1.4825404] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this communication, we would like to test the feasibility of a parallel tempering based study of dissociation in dicationic noble gas clusters, namely, Ar(n)(2+), Kr(n)(2+), and Xe(n)(2+), where "n" is the size of the cluster units. We would like to find out the correct limit for sizes of each of these systems, above which the clusters stay intact as a single unit and does not dissociate into fragments by the process of Coulomb explosion. Moreover, we would also like to, for a specific case, i.e., Ar(n)(2+), study in detail the fragmentation patterns and point out the switchover from the non-fission way to the fission mechanism of dissociation. In all these calculations, we would like to analyse, how close we are in our predictions with that of experimental results. As a further check on the dissociating patterns found out by parallel tempering, we also conduct basin hopping based study on representative sizes of the clusters and find that parallel tempering, as used for this present work as an optimizer, is able to predict correct features when compared with other celebrated methods like the basin hopping algorithm.
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Affiliation(s)
- Srijeeta Talukder
- Department of Chemistry, University of Calcutta, 92 A P C Road, Kolkata 700 009, India
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Julin J, Napari I, Vehkamäki H. Comparative study on methodology in molecular dynamics simulation of nucleation. J Chem Phys 2007; 126:224517. [PMID: 17581073 DOI: 10.1063/1.2740269] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Gas-liquid nucleation of 1000 Lennard-Jones atoms is simulated to evaluate temperature regulation methods and methods to obtain nucleation rate. The Berendsen and the Andersen thermostats are compared. The Berendsen thermostat is unable to control the temperature of clusters larger than the critical size. Independent of the thermostating method the velocities of individual atoms and the translational velocities of clusters up to at least six atoms are accurately described by the Maxwell velocity distribution. Simulations with the Andersen thermostat yield about two times higher nucleation rates than those with the Berendsen thermostat. Nucleation rate is extracted from the simulations by direct observation of times of nucleation onset and by the method of Yasuoka and Matsumoto [J. Chem. Phys. 109, 8451 (1998)]. Compared to the direct observation, the nucleation rates obtained from the method of Yasuoka and Matsumoto are higher by a factor of 3.
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Affiliation(s)
- Jan Julin
- Department of Physical Sciences, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
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Lauri A, Zapadinsky E, Vehkamäki H, Kulmala M. Comparison between the classical theory predictions and molecular simulation results for heterogeneous nucleation of argon. J Chem Phys 2006; 125:164712. [PMID: 17092125 DOI: 10.1063/1.2358343] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We have performed Monte Carlo simulations of homogeneous and heterogeneous nucleations of Lennard-Jones argon clusters. The simulation results were interpreted using the major concept posing a difference between the homogeneous and heterogeneous classical nucleation theories-the contact parameter. Our results show that the multiplication concept of the classical heterogeneous nucleation theory describes the cluster-substrate interaction surprisingly well even for small molecular clusters. However, in the case of argon nucleating on a rigid monolayer of fcc(111) substrate at T=60 K, the argon-substrate atom interaction being approximately one-third as strong as the argon-argon interaction, the use of the classical theory concept results in an underestimation of the heterogeneous nucleation rate by two to three orders of magnitude even for large clusters. The main contribution to this discrepancy is induced by the failure of the classical theory of homogeneous nucleation to predict the energy involved in bringing one molecule from the vapor to the cluster for clusters containing less than approximately 15 molecules.
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Affiliation(s)
- Antti Lauri
- Department of Physical Sciences, University of Helsinki, Finland.
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Krasnochtchekov P, Albe K, Ashkenazy Y, Averback RS. Molecular-dynamics study of the density scaling of inert gas condensation. J Chem Phys 2005; 123:154314. [PMID: 16252955 DOI: 10.1063/1.2074247] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The initial stages of vapor condensation of Ge in the presence of a cold Ar atmosphere were studied by molecular-dynamics simulations. The state variables of interest included the densities of condensing vapor and gas, the density of clusters, and the average cluster size, while the temperatures of the vapor and the clusters were separately monitored with time. Three condensation processes were explicitly identified: nucleation, monomeric growth, and cluster aggregation. Our principal finding is that both the average cluster size and the number of clusters scale with the linear dimension of the computation cell, L, and Ln, with the scaling parameter n approximately 4, corresponding to a reaction order of nu approximately 2.33. This small value of n is explained by an unexpected nucleation path involving the formation of Ge dimers via two-body collisions.
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Affiliation(s)
- P Krasnochtchekov
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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