WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Conference Object Citation - WoS: 12Citation - Scopus: 11Md Study of Energetics, Melting and Isomerization of Aluminum Microclusters(Springer, 2006) Boyukata, Mustafa; Guvenc, Ziya B.Voter and Chen version of an Embedded Atom Model has been applied to study the locally stable structures, energies, melting, isomerization and growth patterns of small aluminum clusters, Al(n), in the size range of n = 2 - 13. Using molecular dynamics and thermal quenching simulations, the global minima and the other locally stable structures have been distinguished from those stationary structures that correspond to saddle points of the potential energy surface. A large number (10000) of independent initial configurations generated at high temperatures has been used to obtain the stable isomers, and the probabilities of sampling different basins of attractions, for each size of the clusters. Their energy spectra have been determined and melting, and isomerization dynamics are investigated.Conference Object Citation - WoS: 2Citation - Scopus: 4Estimation of Cross Sections for Molecule-Cluster Interactions by Using Artificial Neural Networks(Springer, 2006) Boyukata, Mustafa; Kocyigit, Yucel; Guvenc, Ziya B.The cross sections Of D-2 (v,j) + Ni-n (T), n = 19 and 20, collision systems have been estimated by using Artificial Neural Networks (ANNs). For training, previously determined cross section values via molecular dynamics simulation have been used. The performance of the ANNs for predicting any quantities in molecule-cluster interaction has been investigated. Effects of the temperature of the clusters and the rovibrational states of the molecule are analyzed. The results are in good agreement with previous studies.Article Citation - WoS: 58Citation - Scopus: 66Molecular Dynamics Simulation of Sintering and Surface Premelting of Silver Nanoparticles(Japan inst Metals & Materials, 2013) Ozdogan, C.; Hu, A.; Yavuz, M.; Zhou, Y.; Atis, M.; Alarifi, H. A.Sintering of Ag nanoparticles (NPs) is increasingly being used as a driving mechanism for joining in the microelectronics industry. We therefore performed molecular dynamics simulations based on the embedded atom method (EAM) to study pressureless sintering kinetics of two Ag NPs in the size range of (4 to 20 nm), and sintering of three and four Ag NPs of 4 nm diameter. We found that the sintering process passed through three main stages. The first was the neck formation followed by a rapid increase of the neck radius at 50K for 20 nm particles and at 10 K for smaller NPs. The second was characterized by a gradual linear increase of the neck radius to particle radius ratio as the temperature of the sintered structure was increased to the surface premelting point. Different than previous sintering studies, a twin boundary was formed during the second stage that relaxed the sintered structure and decreased the average potential energy (PE). The third stage of sintering was a rapid shrinkage during surface premelting of the sintered structure. Based on pore geometry, densification occurred during the first stage for three 4 nm particles and during the second stage for four 4 nm particles. Sintering rates obtained by our simulation were higher than those obtained by theoretical models generally used for predicting sintering rates of microparticles.Conference Object Citation - WoS: 8Citation - Scopus: 8Dynamics of the D2+ni(100) Collision System: Analysis of the Reactive and Inelastic Channels(Wiley-blackwell, 2001) Böyükata, M; Güvenç, ZB; Jackson, B; Jellinek, JThe reactive and scattering channels of the D(2)(v, j) + Ni(100) collision system are studied using quasiclassical molecular dynamics simulations. The interaction between the D(2) and the atoms of the surface is modeled by a LEPS (London-Eyring-Polani-Sato) potential energy function. The molecule is aimed at three different impact sites (atop, bridge, and center) of a rigid Ni(100) surface along the normal direction with various collision energies less than or equal to1.0 eV. Dissociative chemisorption probabilities are computed for different rotational states of the molecule. Probability distributions of the final rovibrational states of the ground-state Dp molecule scattered from those impact sites are also computed as a function of the collision energy. Higher collision energy results in excitation of higher rotational and/or vibrational states of the scattered molecule. At collision energies below 0.1 eV an indirect dissociation mechanism (through molecular adsorption) dominates the reaction. (C) 2001 John Wiley & Sons, Inc.