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Author Foumani, A.A.; Forster, D.J.; Ghorbanfekr, H.; Weber, R.; Graf, T.; Niknam, A.R.
Title Atomistic simulation of ultra-short pulsed laser ablation of metals with single and double pulses : an investigation of the re-deposition phenomenon Type A1 Journal article
Year (down) 2021 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 537 Issue Pages 147775
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The demand for higher throughput in the processing of materials with ultra-short pulsed lasers has motivated studies on the use of double pulses (DP). It has been observed in such studies that at relatively high time delays between the two pulses, the ablated volume is lower than that for a single pulse (SP). This has been attributed to the shielding of the second pulse and the re-deposition of the material removed by the first pulse. The investigation of re-deposition in copper with the aid of atomistic simulations is the main objective of this study. Nevertheless, a computational investigation of SP-ablation and experimental measurement of the SP-ablation depths and threshold fluence are also covered. The applied computational apparatus comprises a combination of molecular dynamics with the two-temperature model and the Helmholtz wave equation. The analysis of the simulation results shows that the derived quantities like the SP-ablation threshold fluence and the ratio of DP ablation depth to SP-ablation depth are in agreement with the experimental values. An important finding of this study is that the characteristics of the re-deposition process are highly dependent on the fluence.
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Publisher Place of Publication Editor
Language Wos 000582798700006 Publication Date 2020-09-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited 2 Open Access Not_Open_Access
Notes ; The authors thank the Center for High-Performance Computing at Shahid Beheshti University of Iran (SARMAD) for making available the computational resources required for this work. ; Approved Most recent IF: 3.387
Call Number UA @ admin @ c:irua:174299 Serial 6683
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Author Jalali, H.; Ghorbanfekr, H.; Hamid, I.; Neek-Amal, M.; Rashidi, R.; Peeters, F.M.
Title Out-of-plane permittivity of confined water Type A1 Journal article
Year (down) 2020 Publication Physical Review E Abbreviated Journal Phys Rev E
Volume 102 Issue 2 Pages 022803
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The dielectric properties of confined water is of fundamental interest and is still controversial. For water confined in channels with height smaller than h = 8 angstrom, we found a commensurability effect and an extraordinary decrease in the out-of-plane dielectric constant down to the limit of the dielectric constant of optical water. Spatial resolved polarization density data obtained from molecular dynamics simulations are found to be antisymmetric across the channel and are used as input in a mean-field model for the dielectric constant as a function of the height of the channel for h > 15 angstrom. Our results are in excellent agreement with a recent experiment [L. Fumagalli et al., Science 360, 1339 (2018)].
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Publisher Place of Publication Editor
Language Wos 000560660400004 Publication Date 2020-08-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1539-3755; 1550-2376 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.366 Times cited 25 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:171157 Serial 6574
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Author Ghorbanfekr, H.; Behler, J.; Peeters, F.M.
Title Insights into water permeation through hBN nanocapillaries by ab initio machine learning molecular dynamics simulations Type A1 Journal article
Year (down) 2020 Publication Journal Of Physical Chemistry Letters Abbreviated Journal J Phys Chem Lett
Volume 11 Issue 17 Pages 7363-7370
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Water permeation between stacked layers of hBN sheets forming 2D nanochannels is investigated using large-scale ab initio-quality molecular dynamics simulations. A high-dimensional neural network potential trained on density-functional theory calculations is employed. We simulate water in van der Waals nanocapillaries and study the impact of nanometric confinement on the structure and dynamics of water using both equilibrium and nonequilibrium methods. At an interlayer distance of 10.2 A confinement induces a first-order phase transition resulting in a well-defined AA-stacked bilayer of hexagonal ice. In contrast, for h < 9 A, the 2D water monolayer consists of a mixture of different locally ordered patterns of squares, pentagons, and hexagons. We found a significant change in the transport properties of confined water, particularly for monolayer water where the water-solid friction coefficient decreases to half and the diffusion coefficient increases by a factor of 4 as compared to bulk water. Accordingly, the slip-velocity is found to increase under confinement and we found that the overall permeation is dominated by monolayer water adjacent to the hBN membranes at extreme confinements. We conclude that monolayer water in addition to bilayer ice has a major contribution to water transport through 2D nanochannels.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000569375400061 Publication Date 2020-08-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1948-7185 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.7 Times cited 24 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program (Grant Number: G099219N). The authors thank Arham Amouei for the helpful discussion regarding MD simulations. ; Approved Most recent IF: 5.7; 2020 IF: 9.353
Call Number UA @ admin @ c:irua:171996 Serial 6546
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