Simulation of dynamic growth rate of focused ion beam-induced deposition using Hausdorff distance

2019 ◽  
Vol 286 ◽  
pp. 169-177
Author(s):  
Kang-In Lee ◽  
Hyun-Taek Lee ◽  
Ki-Hwan Jang ◽  
Sung-Hoon Ahn
Keyword(s):  
Growth Rate ◽  
Hausdorff Distance ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Dynamic Growth ◽  
Dynamic Growth Rate

scholarly journals Optimization of Pt-C Deposits by Cryo-FIBID: Substantial Growth Rate Increase and Quasi-Metallic Behaviour

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1906 ◽  
Author(s):  
Alba Salvador-Porroche ◽  
Soraya Sangiao ◽  
Patrick Philipp ◽  
Pilar Cea ◽  
José María De Teresa
Keyword(s):  
Growth Rate ◽  
Electrical Resistivity ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Electrical Contacts ◽  
Condensation Temperature ◽  
Monte Carlo Code ◽  
Condensed Layer

The Focused Ion Beam Induced Deposition (FIBID) under cryogenic conditions (Cryo-FIBID) technique is based on obtaining a condensed layer of precursor molecules by cooling the substrate below the condensation temperature of the gaseous precursor material. This condensed layer is irradiated with ions according to a desired pattern and, subsequently, the substrate is heated above the precursor condensation temperature, revealing the deposits with the shape of the exposed pattern. In this contribution, the fast growth of Pt-C deposits by Cryo-FIBID is demonstrated. Here, we optimize various parameters of the process in order to obtain deposits with the lowest-possible electrical resistivity. Optimized ~30 nm-thick Pt-C deposits are obtained using ion irradiation area dose of 120 μC/cm2 at 30 kV. This finding represents a substantial increment in the growth rate when it is compared with deposits of the same thickness fabricated by standard FIBID at room temperature (40 times enhancement). The value of the electrical resistivity in optimized deposits (~4 × 104 µΩ cm) is suitable to perform electrical contacts to certain materials. As a proof of concept of the potential applications of this technology, a 100 µm × 100 µm pattern is carried out in only 43 s of ion exposure (area dose of 23 μC/cm2), to be compared with 2.5 h if grown by standard FIBID at room temperature. The ion trajectories and the deposit composition have been simulated using a binary-collision-approximation Monte Carlo code, providing a solid basis for the understanding of the experimental results.

scholarly journals Corrosion pitting and environmentally assisted small crack growth

2014 ◽  
Vol 470 (2169) ◽  
pp. 20140254 ◽  
Author(s):  
Alan Turnbull
Keyword(s):  
Growth Rate ◽  
Stress Corrosion ◽  
Focused Ion Beam ◽  
Imaging Techniques ◽  
Ion Beam ◽  
Critical Factor ◽  
Potential Drop ◽  
Quantitative Prediction ◽  
Local Dynamic ◽  
Element Analysis

In many applications, corrosion pits act as precursors to cracking, but qualitative and quantitative prediction of damage evolution has been hampered by lack of insights into the process by which a crack develops from a pit. An overview is given of recent breakthroughs in characterization and understanding of the pit-to-crack transition using advanced three-dimensional imaging techniques such as X-ray computed tomography and focused ion beam machining with scanning electron microscopy. These techniques provided novel insights with respect to the location of crack development from a pit, supported by finite-element analysis. This inspired a new concept for the role of pitting in stress corrosion cracking based on the growing pit inducing local dynamic plastic strain, a critical factor in the development of stress corrosion cracks. Challenges in quantifying the subsequent growth rate of the emerging small cracks are then outlined with the potential drop technique being the most viable. A comparison is made with the growth rate for short cracks (through-thickness crack in fracture mechanics specimen) and long cracks and an electrochemical crack size effect invoked to rationalize the data.

scholarly journals On selection-regulated population dynamics in birds and mammals

2021 ◽  
Author(s):  
Lars Witting
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Population Dynamic ◽  
North American ◽  
Dynamic Equilibrium ◽  
New Paradigm ◽  
Breeding Bird ◽  
The North ◽  
Dynamic Growth ◽  
Dynamic Growth Rate

I use the North American Breeding Bird Survey (Sauer et al. 2017) to construct 462 population trajectories with about 50 yearly abundance estimates each. Applying AIC model-selection, I find that selection-regulated population dynamics is 25,000 (95%:0.42-1.7e17) times more probable than density-regulated growth. Selection is essential in 94% of the best models explaining 82% of the population dynamics variance across the North American continent. Similar results are obtained for 111, 215, and 420 populations of British birds (BTO 2020), Danish birds (DOF 2020), and birds and mammals in the Global Population Dynamic Database (GPDD 2010). The traditional paradigm---that the population dynamic growth rate is a function of the environment, with maximal per-capita growth at low population densities, and sub-optimal reproduction from famine at carrying capacities with strong competition for limited resources---is not supported. Selection regulation generates a new paradigm where the world is green and individuals are selected to survive and reproduce at optimal levels at population dynamic equilibria with sufficient resources. It is only the acceleration of the population dynamic growth rate, and not the growth rate itself, that is determined by the density-dependent environment, with maximal growth occurring at the densities of the population dynamic equilibrium.

Determination of anti-Aspergillus activity of antifungal agents based on the dynamic growth rate of a single hypha

1993 ◽  
Vol 39 (3) ◽  
Author(s):  
Kibong Oh ◽  
Hideaki Matsuoka ◽  
Yasuyuki Nemoto ◽  
Osao Sumita ◽  
Kosuke Takatori ◽  
...  
Keyword(s):  
Growth Rate ◽  
Antifungal Agents ◽  
Dynamic Growth ◽  
Single Hypha ◽  
Dynamic Growth Rate

scholarly journals In situ 3D comparison of Chlorella pyrenoidosa with nuclear-irradiated mutagenic strains by using focused ion beam milling and cryo-electron tomography

2020 ◽  
Author(s):  
Wangbiao Guo ◽  
Lingchong Feng ◽  
Zhenyi Wang ◽  
Jiansheng Guo ◽  
Donghyun Park ◽  
...  
Keyword(s):  
Growth Rate ◽  
Focused Ion Beam ◽  
Electron Tomography ◽  
Ion Beam ◽  
Chlorella Pyrenoidosa ◽  
Biofuel Production ◽  
Full Potential ◽  
Wide Range ◽  
Cryo Electron Tomography ◽  
Mutant Cells

AbstractMicroalgae are highly efficient photosynthetic organisms that hold enormous potential as sources of renewable energy. In particular, Chlorella pyrenoidosa displays a rapid growth rate, high tolerance to light, and high lipid content, making it especially valuable for applications such as flue gas CO2 fixation, biofuel production, and nutritional extracts. In order to unveil its full potential, it is necessary to characterize its subcellular architecture. Here, we achieved three-dimensional (3D) visualization of the architectures of C. pyrenoidosa cells, by combining focused ion beam scanning electron microscopy (FIB/SEM), cryo-FIB milling, and cryo-electron tomography (cryo-ET). These high-resolution images bring to light intricate features of intact organelles, including thylakoid membranes, pyrenoid, starch granules, mitochondria, nucleus, lipid droplets and vacuoles, as well as the fine architectures within the chloroplast, including the concave-convex pyrenoid, plastoglobules, thylakoid tips, and convergence zones. Significantly, comparative analysis of wild-type and nuclear-irradiated mutagenic strains determined that cell volume and surface area of mutant cells have increased substantially to 2.2-fold and 1.7-fold, respectively, consistent with up-regulation of the enzyme Rubisco and enhanced photosynthetic metabolic processes. Moreover, quantitative analysis established that the thylakoid membrane width in mutant cells increased to 1.3-fold, while the membrane gap decreased to 0.8-fold, possibly contributing to the higher biomass growth rate of mutant cells. Our work reveals the first 3D subcellular architectures of C. pyrenoidosa cell and provides a structural framework for unlocking the higher growth rate in microalgae relevant to a wide range of industrial applications.

An Analysis of Tungsten FIB-Fabricated Via Resistance

2008 ◽  
Author(s):  
David W. Niles ◽  
Jay Meyer ◽  
Ronald W. Kee ◽  
Michael DiBattista
Keyword(s):  
Growth Rate ◽  
Aspect Ratio ◽  
Focused Ion Beam ◽  
Flat Surface ◽  
Ion Beam ◽  
Effective Area ◽  
Flat Surfaces ◽  
Least Squares Fit ◽  
Resistance Model ◽  
Resistance Data

Abstract We present an analysis of tungsten vias fabricated by a focused ion beam with regard to the understanding of circuit editing strategies. The growth rate of W is ~10 times faster in high aspect ratio vias than on flat surfaces, and W in vias has 4 at. % more C but only one-tenth the Ga of surface-deposited W. We propose that vias act like small Faraday cups, trapping the energy of the Ga+ ions and the reaction byproducts to enhance the growth rate of W and to increase the C to W ratio in vias compared to flat surfaces. The resistivity of W in the vias determined by a least squares fit to resistance data is 250μΩ-cm, unchanged from the resistivity of W deposited on a flat surface. The resistances of the vias fabricated in a SiO2 layer to contact an underlying Al sheet layer fit well to either of two models: 1) an effective area model that invokes resistive via sidewalls that do not participate in conduction, and 2) an contact resistance model that invokes tapered vias with a constricted W/Al contact area.

Dynamic Growth Rate Behavior of a Carbon Nanotube Forest Characterized by in Situ Optical Growth Monitoring

Nano Letters ◽  
2003 ◽  
Vol 3 (6) ◽  
pp. 863-865 ◽  
Author(s):  
Do-Hyung Kim ◽  
Hoon-Sik Jang ◽  
Chang-Duk Kim ◽  
Dong-Soo Cho ◽  
Hee-Sun Yang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Carbon Nanotube ◽  
Growth Monitoring ◽  
Rate Behavior ◽  
Dynamic Growth ◽  
Dynamic Growth Rate

scholarly journals High-Selectivity Growth of GaN Nanorod Arrays by Liquid-Target Magnetron Sputter Epitaxy

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 719
Author(s):  
Elena Alexandra Serban ◽  
Aditya Prabaswara ◽  
Justinas Palisaitis ◽  
Per Ola Åke Persson ◽  
Lars Hultman ◽  
...  
Keyword(s):  
Growth Rate ◽  
Focused Ion Beam ◽  
High Selectivity ◽  
Ion Beam ◽  
Substrate Surface ◽  
Growth Control ◽  
High Growth ◽  
Si Substrates ◽  
Surface Diffusivity ◽  
Magnetron Sputter

Selective-area grown, catalyst-free GaN nanorod (NR) arrays grown on Si substrates have been realized using liquid-target reactive magnetron sputter epitaxy (MSE). Focused ion beam lithography (FIBL) was applied to pattern Si substrates with TiNx masks. A liquid Ga target was sputtered in a mixture gas of Ar and N2, ranging the N2 partial pressure (PN₂) ratio from 100% to 50%. The growth of NRs shows a strong correlation with PN₂ on the selectivity, coalescence, and growth rate of NRs in both radial and axial directions. The growth rate of NRs formed inside the nanoholes increases monotonically with PN₂. The PN₂ ratio between 80% and 90% was found to render both a high growth rate and high selectivity. When the PN₂ ratio was below 80%, multiple NRs were formed in the nanoholes. For a PN₂ ratio higher than 90%, parasitic NRs were grown on the mask. An observed dependence of growth behavior upon the PN₂ ratio is attributed to a change in the effective Ga/N ratio on the substrate surface, as an effect of impinging reactive species, surface diffusivity, and residence time of adatoms. The mechanism of NR growth control was further investigated by studying the effect of nanoholes array pitch and growth temperature. The surface diffusion and the direct impingement of adatoms were found to be the dominant factors affecting the lateral and axial growth rates of NR, respectively, which were well elucidated by the collection area model.

scholarly journals Study of the initial stage of GaAs growth on FIB-modified silicon substrates

2021 ◽  
Vol 2086 (1) ◽  
pp. 012007
Author(s):  
M M Eremenko ◽  
N A Shandyba ◽  
N E Chernenko ◽  
M S Solodovnik ◽  
S V Balakirev ◽  
...  
Keyword(s):  
Growth Rate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Gaas Layer ◽  
Implantation Dose ◽  
Silicon Substrates ◽  
One Dimensional ◽  
Growth Regime ◽  
Initial Stage ◽  
Deposition Thickness

Abstract In this work, we studied the effect of the deposition thickness, growth rate, arsenic flux, and implantation dose on the morphology of the GaAs nanostructures grown on modified Si areas. It is shown that an increase in the growth rate at the initial stages of the growth process leads to the transition of the growth regime from layered-like to one-dimensional with the formation of nanowires. Studies of the effect of As4 pressure have shown that a change in the equivalent As4 flux in the range of 3.7 - 5.0 ML/s does not lead to any significant change in the structure of the GaAs layer in the modified areas. An increase in the implantation dose during processing with a focused ion beam led to disordering of the directions of the grown nanowires due to the degradation of the substrate crystal structure.

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