scholarly journals Peeling graphite layer by layer reveals the charge exchange dynamics of ions inside a solid

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Anna Niggas ◽  
Sascha Creutzburg ◽  
Janine Schwestka ◽  
Benjamin Wöckinger ◽  
Tushar Gupta ◽  
...  
Keyword(s):  
Charge State ◽  
Delta Function ◽  
Niels Bohr ◽  
Layer By Layer ◽  
Graphite Layer ◽  
Major Step ◽  
Equilibrium Charge ◽  
Excitation Processes ◽  
Trilayer Graphene ◽  
Charged Ions

AbstractOver seventy years ago, Niels Bohr described how the charge state of an atomic ion moving through a solid changes dynamically as a result of electron capture and loss processes, eventually resulting in an equilibrium charge state. Although obvious, this process has so far eluded direct experimental observation. By peeling a solid, such as graphite, layer by layer, and studying the transmission of highly charged ions through single-, bi- and trilayer graphene, we can now observe dynamical changes in ion charge states with monolayer precision. In addition we present a first-principles approach based on the virtual photon model for interparticle energy transfer to corroborate our findings. Our model that uses a Gaussian shaped dynamic polarisability rather than a spatial delta function is a major step in providing a self-consistent description for interparticle de-excitation processes at the limit of small separations.

Layer-by-layer analysis of charge state distribution of field evaporated ions from the W(011) plane

1984 ◽  
Vol 140 (1) ◽  
pp. L253-L258
Author(s):  
Kenji Murakami ◽  
Toshiyuki Adachi ◽  
Tsukasa Kuroda ◽  
Shogo Nakamura
Keyword(s):  
Charge State ◽  
Charge State Distribution ◽  
Layer By Layer ◽  
State Distribution ◽  
Layer Analysis

scholarly journals Large-Scale Molecular Dynamics Simulations Reveal New Insights Into the Phase Transition Mechanisms in MIL-53(Al)

2021 ◽  
Vol 9 ◽  
Author(s):  
Sander Vandenhaute ◽  
Sven M. J. Rogge ◽  
Veronique Van Speybroeck
Keyword(s):  
Large Scale ◽  
Pressure Control ◽  
Layer By Layer ◽  
Major Step ◽  
Transition Mechanism ◽  
External Pressures ◽  
Pressure Regime ◽  
Dynamics Simulations ◽  
Experimental Crystal ◽  
External Stimuli

Soft porous crystals have the ability to undergo large structural transformations upon exposure to external stimuli while maintaining their long-range structural order, and the size of the crystal plays an important role in this flexible behavior. Computational modeling has the potential to unravel mechanistic details of these phase transitions, provided that the models are representative for experimental crystal sizes and allow for spatially disordered phenomena to occur. Here, we take a major step forward and enable simulations of metal-organic frameworks containing more than a million atoms. This is achieved by exploiting the massive parallelism of state-of-the-art GPUs using the OpenMM software package, for which we developed a new pressure control algorithm that allows for fully anisotropic unit cell fluctuations. As a proof of concept, we study the transition mechanism in MIL-53(Al) under various external pressures. In the lower pressure regime, a layer-by-layer mechanism is observed, while at higher pressures, the transition is initiated at discrete nucleation points and temporarily induces various domains in both the open and closed pore phases. The presented workflow opens the possibility to deduce transition mechanism diagrams for soft porous crystals in terms of the crystal size and the strength of the external stimulus.

Equilibrium charge-state distributions for 16O ions at 20–65 MeV

1975 ◽  
Vol 124 (2) ◽  
pp. 317-319 ◽  
Author(s):  
David J. Weber ◽  
Norton M. Hintz ◽  
D. Dehnhard
Keyword(s):  
Charge State ◽  
Equilibrium Charge ◽  
Charge State Distributions

scholarly journals Study on the electron configuration and the average equilibrium charge-state of highly charged Kr13+ ion

2014 ◽  
Vol 488 (13) ◽  
pp. 132034
Author(s):  
Cexiang Mei ◽  
Xiaoan Zhang ◽  
Yongtao Zhao ◽  
Jieru Ren ◽  
Xianming Zhou ◽  
...  
Keyword(s):  
Charge State ◽  
Electron Configuration ◽  
Equilibrium Charge

Electron Collisions with Highly Charged Ions: General Theory and Excitation Processes

1985 ◽  
pp. 55-77 ◽  
Author(s):  
Ratko K. Janev ◽  
Leonid P. Presnyakov ◽  
Vjatcheslav P. Shevelko
Keyword(s):  
General Theory ◽  
Highly Charged Ions ◽  
Electron Collisions ◽  
Excitation Processes ◽  
Charged Ions

scholarly journals Electrophoretic Deposition of Layer-by-Layer Unsheathed Carbon Nanotubes—A Step Towards Steerable Surface Roughness and Wettability

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 595 ◽  
Author(s):  
Emil Korczeniewski ◽  
Monika Zięba ◽  
Wojciech Zięba ◽  
Anna Kolanowska ◽  
Paulina Bolibok ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Electrophoretic Deposition ◽  
Fiber Surface ◽  
Deposition Process ◽  
Layer By Layer ◽  
Major Step ◽  
Multiwalled Carbon ◽  
Water Contact ◽  
Wide Range

It is well known that carbon nanotube (CNT) oxidation (usually with concentrated HNO3) is a major step before the electrophoretic deposition (EPD). However, the recent discovery of the “onion effect” proves that multiwalled carbon nanotubes are not only oxidized, but a simultaneous unsheathing process occurs. We present the first report concerning the influence of unsheathing on the properties of the thus-formed CNT surface layer. In our study we examine how the process of gradual oxidation/unsheathing of a series of multiwalled carbon nanotubes (MWCNTs) influences the morphology of the surface formed via EPD. Taking a series of well-characterized and gradually oxidized/unsheathing Nanocyl™ MWCNTs and performing EPD on a carbon fiber surface, we analyzed the morphology and wettability of the CNT surfaces. Our results show that the water contact angle could be gradually changed in a wide range (125–163°) and the major property determining its value was the diameter of aggregates formed before the deposition process in the solvent. Based on the obtained results we determined the parameters having a crucial influence on the morphology of created layers. Our results shed new light on the deposition mechanism and enable the preparation of surfaces with steerable roughness and wettability.

Layer-by-layer analysis of charge state distribution of field evaporated ions from the W(011) plane

1984 ◽  
Vol 140 (1) ◽  
pp. L253-L258 ◽  
Author(s):  
Kenji Murakami ◽  
Toshiyuki Adachi ◽  
Tsukasa Kuroda ◽  
Shogo Nakamura
Keyword(s):  
Charge State ◽  
Charge State Distribution ◽  
Layer By Layer ◽  
State Distribution ◽  
Layer Analysis

scholarly journals Charge equilibrium of fast heavy ions traversing through gaseous media

1984 ◽  
Vol 2 (4) ◽  
pp. 477-483
Author(s):  
S. Karashima ◽  
T. Watanabe
Keyword(s):  
Charge State ◽  
Hydrogen Gas ◽  
Electron Loss ◽  
Equilibrium Conditions ◽  
Equilibrium Charge ◽  
Gas Target ◽  
Gaseous Media ◽  
Ion Ranges ◽  
Non Local ◽  
Made In

The charge distribution of an incident ion as a function of projectile velocity, its range and its average equilibrium charge are studied theoretically. The calculations are made only for an atomic hydrogen gas target. The charge of the ion is determined by the equilibrium between electron loss from the ion and electron capature from a hydrogen atom to the ion. The charge states of the ions are calculated in two cases; to assume a local balance condition for electron loss and capture and to solve a rate equation for the charge state fraction function under non-local balance conditions, both only taking into account single electron loss and capture processes. In the calculations we use empirical formulae for electron loss and capture cross section by making some simplifications. Calculations for the charge state fraction as functions of ion ranges under non-equilibrium conditions have been carried out in the cases of Ne, Ar, and Xe ions. Calculations for the charge state under local balance conditions have been made in the cases of C, Ne, Ar, Kr, I, and U ions.

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