Determining phase transition using potential energy distribution and surface energy of Pd nanoparticles

Azadeh, Maryam; Kateb, Movaffaq; Marashi, Pirooz

doi:10.1016/j.commatsci.2019.109187

Cited by 12 publications

(12 citation statements)

References 50 publications

(88 reference statements)

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“…We considered the common neighbor analysis (CNA) method [60,61,62] to characterize the local structure. CNA allows us to distinguish between face centered cubic (fcc) and hexagonal close-packed (hcp) structures which is of practical importance in defect analysis [63,64]. This is achieved by de-termining the angles between the nearest neighbors, and thus the fcc and hcp lattices, having central and mirror symmetry in (111) planes, respectively, can be distinguished by a slight angle difference.…”

Section: Methodsmentioning

confidence: 99%

On the role of ion potential energy in low energy HiPIMS deposition: An atomistic simulation

Kateb

Guðmundsson

Brault

et al. 2021

Surface and Coatings Technology

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We study the effect of the so-called ion potential or non-kinetic energies of bombarding ions during ionized physical vapor deposition of Cu using molecular dynamics simulations. In particular we focus on low energy high power impulse magnetron sputtering (HiPIMS) deposition, in which the potential energy of ions can be comparable to their kinetic energy. The ion potential, as a shortranged repulsive force between the ions of the film-forming material and the surface atoms (substrate and later deposited film), is defined by the Ziegler-Biersack-Littmark potential. Analyzing the final structure indicates that, including the ion potential leads to a slightly lower interface mixing and fewer point defects (such as vacancies and interstitials), but resputtering and twinning have increased slightly. However, by including the ion potential the collision pattern changes. We also observed temporary formation of a ripple/pore with 5 nm height when the ion potential is included. The latter effect can explain the pores that have been observed experimentally in HiPIMS deposited Cu thin films by atomic force microscopy.

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Section: Methodsmentioning

confidence: 99%

On the role of ion potential energy in low energy HiPIMS deposition: An atomistic simulation

Kateb

Guðmundsson

Brault

et al. 2021

Surface and Coatings Technology

Self Cite

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show abstract

“…We considered the common neighbor analysis (CNA) method [58,59,60] to characterize the local structure. CNA allows us to distinguish between fcc and hcp structures which is of practical importance in defect analysis [61,62]. This is achieved by determining the angles between the nearest neighbors, and thus the fcc and hcp lattices, having central and mirror symmetry in (111) planes, respectively, can be distinguished by a slight angle difference.…”

Section: Methodsmentioning

confidence: 99%

On the role of ion potential energy in low energy HiPIMS deposition: An atomistic simulation

Kateb¹,

Guðmundsson²,

Brault³

et al. 2021

Preprint

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We study the effect of the so-called ion potential or non-kinetic energies of bombarding ions during ionized physical vapor deposition of Cu using molecular dynamics simulations. In particular we focus on low energy HiPIMS deposition, in which the potential energy of ions can be comparable to their kinetic energy. The ion potential, as a short-ranged repulsive force between the ions of the film-forming material and the surface atoms (substrate and later film), is defined by the Ziegler-Biersack-Littmark potential. Analyzing the final structure indicates that, including the ion potential leads to a slightly lower interface mixing and fewer point defects (such as vacancies and interstitials), but resputtering and twinning have increased slightly. However, by including the ion potential the collision pattern changes. We also observed temporary formation of a ripple/pore with 5 nm height when the ion potential is included. The latter effect can explain the pores in HiPIMS deposited Cu thin films observed experimentally by atomic force microscopy.

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“…The most common structure characterization is to utilize the radial distribution function, g(r). 64,65 In order to study the film-substrate interface quantitatively, we utilized partial g(r), g ij (r). This approach was originally introduced by Ashcroft and Langreth 66 for analyzing binary mixtures.…”

Section: Methodsmentioning

confidence: 99%

“…Besides, it allows distinction between fcc and hcp which is of practical importance in defect analysis. 64,65 Briefly, the CNA determines local crystal structure based on decomposition of 1st nearest neighbors (NNs), from 1st g(r) peak, into different angles. Thus, CNA is sensitive to angles between pairs of NNs and can distinguish between fcc and hcp structure.…”

Section: Methodsmentioning

confidence: 99%

Effect of substrate bias on microstructure of epitaxial film grown by HiPIMS: An atomistic simulation

Kateb¹,

Guðmundsson²,

Ingvarsson³

2020

Preprint

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We explore combination of high power impulse magnetron sputtering (HiPIMS) and substrate bias for the epitaxial growth of Cu film on Cu (111) substrate by molecular dynamics simulation. A fully ionized deposition flux was used to represent the high ionization fraction in the HiPIMS process. To mimic different substrate bias, we assumed the deposition flux with a flat energy distribution in the low, moderate and high energy ranges. We also compared the results of fully ionized flux with results assuming a completely neutral flux, in analogy with thermal evaporation. It is confirmed that in the low energy regime, HiPIMS presents a slightly smoother surface and more interface mixing compared to that of thermal evaporation. In the moderate energy HiPIMS, however, an atomically smooth surface was obtained with a slight increase in the interface mixing compared to low energy HiPIMS. In the high energy regime, HiPIMS presents severe interface mixing with a smooth surface but limited growth due to resputtering from the surface. The results also indicate that fewer crystal defects appear in the film for moderate energy HiPIMS. We attribute this behavior to the repetition frequency of collision events. In particular high energy HiPIMS suffers from high repetition of collision events which does not allow reconstruction of the film. While in the low energy HiPIMS there are not enough events to overcome island growth. At moderate energy, collision events repeat in a manner that provides enough time for reconstruction which results in a smooth surface, fewer defects and limited intermixing.

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Determining phase transition using potential energy distribution and surface energy of Pd nanoparticles

Cited by 12 publications

References 50 publications

On the role of ion potential energy in low energy HiPIMS deposition: An atomistic simulation

On the role of ion potential energy in low energy HiPIMS deposition: An atomistic simulation

On the role of ion potential energy in low energy HiPIMS deposition: An atomistic simulation

Effect of substrate bias on microstructure of epitaxial film grown by HiPIMS: An atomistic simulation

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