INFORMATION SUPPORT FOR DECISION-MAKING IN THE PRODUCTION OF THE CATALYST FOR THE SYNTHESIS OF CARBON NANOTUBES

The aim of the study is to develop information systems for supporting and supporting decision-making in the production of a metal oxide catalyst that provides targeted synthesis of carbon nanotubes by gas-phase chemical deposition. To achieve the goal, the following tasks were solved: a new approach to the process of creating a catalyst for the thermal decomposition of unstable compounds for synthetic nanotubes was developed; experimental studies of the effect on the post-thermal treatment of the catalyst and its precursors by physical action (ultrasonic, electromagnetic and microwave fields, etc.), which were obtained the approximating characteristics of the synthesized models of carbon nanostructures on the parameters of the process of pre- and post-thermal treatment of the catalyst were used to create a recommendation module. On the basis of the results obtained, blocks of implementation and technologies were developed, used in the creation of a system for maintaining and supporting solutions for the production of a catalyst for synthetic nanotubes. The application of the developed system of maintenance and support of decisions makes it possible to form a catalyst that makes it possible to synthesize carbon nanotubes with specified characteristics. Also, the use of this information system in the production of a catalyst helps to expand the range of synthesized nanoproducts in the process of gas-phase chemical deposition without changing the composition of the catalyst.

Download Full-text

Solvent-free thermoplastic-poly(dimethylsiloxane) bonding mediated by UV irradiation followed by gas-phase chemical deposition of an adhesion linker

Journal of Micromechanics and Microengineering ◽

10.1088/0960-1317/25/7/075007 ◽

2015 ◽

Vol 25 (7) ◽

pp. 075007 ◽

Cited By ~ 7

Author(s):

S Y Ahn ◽

N Y Lee

Keyword(s):

Gas Phase ◽

Uv Irradiation ◽

Chemical Deposition ◽

Solvent Free ◽

Phase Chemical

Download Full-text

Flame Synthesis of Carbon Nanotubes and Nano-Onions in a Rotating Opposed-Jets Flow

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.284-287.310 ◽

2013 ◽

Vol 284-287 ◽

pp. 310-314 ◽

Cited By ~ 1

Author(s):

Shuhn Shyurng Hou ◽

Wei Cheng Huang

Keyword(s):

Carbon Nanotubes ◽

Strain Rate ◽

Residence Time ◽

Carbon Nanostructures ◽

Diffusion Flames ◽

Carbon Sources ◽

Ni Substrate ◽

Nano Structures ◽

Lower Strain ◽

Synthesis Of Carbon Nanotubes

The influence of flow rotation on the synthesis of carbon nano-structures using rotating opposed flow ethylene diffusion flames and a catalytic Ni substrate was investigated. In the experiments, the flame parameter was kept constant with fuel and oxidizer compositions of 20%C2H2+80%N2 and 40%O2+60%N2 in the upper and lower burners, respectively, whereas the strain rate was varied by adjusting the rotation speed. Stain rate affects carbon nano-structures synthesis either through the residence time of the flow or carbon sources available for the growth of carbon nanotubes (CNTs) and onions. A diffusion flame at low strain rate is stronger than a weak flame at high strain rate and produces more carbon sources because of the longer residence time of the flow. At a higher strain rate, curved and entangled tubular multi-walled CNTs were harvested, however, at a lower strain rate carbon nano-onions (CNOs) were synthesized. It is verified that flow rotation associated with residence time plays an important role in the synthesis of carbon nanostructures.

Download Full-text

EFFECT OF PASSIVATING COATINGS ON METALLIZATION TOPOLOGY IN PRODUCTION OF SEMICONDUCTOR DEVICES

Izvestia Ufimskogo Nauchnogo Tsentra RAN ◽

10.31040/2222-8349-2021-0-4-30-34 ◽

2021 ◽

Vol 0 (4) ◽

pp. 30-34

Author(s):

M.V. POTAPOVA ◽

◽

M.YU. MAKHMUD-AKHUNOV ◽

V.N. GOLOVANOV ◽

K.E. IMESHEV ◽

...

Keyword(s):

Gas Phase ◽

Silicon Oxide ◽

Semiconductor Device ◽

Semiconductor Devices ◽

Experimental Studies ◽

Chemical Deposition ◽

Aluminum Film ◽

Single Crystal Substrate ◽

Plasma Chemical ◽

Aluminum Metallization

The surface quality of the metallized contact pads on the crystal plays an important role in the production of semiconductor devices. This paper presents experimental studies of the effect of a protective passivation film of silicon oxide on the surface structure of aluminum metallization in the field of forming contact pads. Plasma chemical deposition of passivation layer SiO2 from gas phase (PECVD method) was carried out on prepared samples of silicon with aluminum metallization using a high-frequency power source with a frequency of 13.56 MHz. After that, chemical etching of precipitated silicon oxide was carried out to simulate the process of forming contact areas of semiconductor device crystals. The resistance of the metallization surface to plasma processes was studied by raster electron microscopy. It is shown that as a result of the process cycle, defects of the dislocation type are generated in the applied film Al. The nature of the observed defects has been found to be different. The revealed large square-shaped pits with a size of ~ 1 μm at the places where dislocations come to the surface are of a single nature and appear independently of the processes of applying passivation coatings, which is determined by the orienting action of a single-crystal substrate having some low dislocation density. While the second type of defects, shown by the presence of etching pits measuring ~ 100-300 nm, is characterized by a higher surface density. Moreover, the exclusion of the passivation process with silicon oxide did not lead to the appearance of this type of defects, which determined their nature associated with the ion bombardment of the Al layer during the plasma chemical deposition of silicon oxide from the gas phase. It is also shown that a feature of this type of defects is their disorientation both with respect to the first type of defects and with respect to each other. Detection of the structure of the metallization layers was carried out by X-ray diffraction, the results of which show the polycrystallinity of the formed aluminum metallization. The preferred orientation of the aluminum film corresponds to the substrate Si (111).

Download Full-text

Improvement of Electron Field Emission from Carbon Nanotubes by Ba(NO3)2 Treatment

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.386.116 ◽

2018 ◽

Vol 386 ◽

pp. 116-121

Author(s):

Evgeny Kitsyuk ◽

Egor Lebedev ◽

Andrey Nartov ◽

Roman Ryazanov ◽

Artemiy Shamanaev

Keyword(s):

Carbon Nanotubes ◽

Gas Phase ◽

Field Emission ◽

Threshold Voltage ◽

Chemical Deposition ◽

Thin Layers ◽

Electron Field Emission ◽

Electron Field ◽

Cnt Arrays ◽

Emission Threshold

The method of manufacturing BaO thin layers on carbon nanotubes (CNT) from Ba(NO3)2 aqueous solutions was demonstrated. Ordered carbon nanotubes arrays were synthesized by catalytic plasma-stimulated chemical deposition from the gas phase. The influence of the BaO content on the work function and, accordingly, carbon nanotubes emission properties were investigated. Significant field emission threshold voltage of CNT arrays treated by solutions with the lowest Ba(NO3)2 concentrations was demonstrated.

Download Full-text

Carbon Nanotubes Grown with Non-Ferromagnetic Catalysts in Alcohol CVD

Materials Science Forum ◽

10.4028/www.scientific.net/msf.636-637.703 ◽

2010 ◽

Vol 636-637 ◽

pp. 703-708 ◽

Cited By ~ 2

Author(s):

E. Borowiak-Palen ◽

A. Steplewska ◽

A. Bachmatiuk ◽

M.H. Rümmeli ◽

R.K. Kalenczuk

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Carbon Nanostructures ◽

Vapour Deposition ◽

Chemical Vapour ◽

Iron Catalysts ◽

Multiwalled Carbon ◽

Experimental Conditions ◽

Transmission Electron ◽

Synthesis Of Carbon Nanotubes

In this contribution we present high resolution transmission electron microscopy (HR-TEM) and Raman studies on the synthesis of carbon nanotubes using platinum supported on MgO in alcohol - chemical vapour deposition (A-CVD). For comparison copper and iron catalysts mixed with the same metal loading in MgO and the same process parameters in A-CVD have been tested. Our findings show that the choice of catalyst utilized under the same experimental conditions strongly influences the final morphology of the carbon nanostructures. Application of Pt/MgO in CVD results in doublewalled carbon nanotubes (DWCNT) and multiwalled carbon nanotubes (MWCNT). Cu/MgO mixtures lead to the synthesis of copper filled multiwalled carbon nanotubes (Cu-MWCNT) and iron capsules surrounded by multiwalled carbon shells (Fe-MWCS), respectively. Our findings indicate that the three discussed metals interact differently with the substrate leading to the formation of different sized catalyst particles. The analysis of the particles size in the catalyst precursors and in the final products is also described in this contribution.

Download Full-text

Methods for the chemical synthesis of carbon nanotubes: an approach based on hemispherical polyarene templates

Pure and Applied Chemistry ◽

10.1515/pac-2016-1222 ◽

2017 ◽

Vol 89 (6) ◽

pp. 809-820 ◽

Cited By ~ 5

Author(s):

Lawrence T. Scott

Keyword(s):

Carbon Nanotubes ◽

Gas Phase ◽

Large Diameter ◽

Small Diameter ◽

Diels Alder ◽

Promising Candidate ◽

Benzene Rings ◽

End Caps ◽

Synthesis Of Carbon Nanotubes ◽

Walled Carbon Nanotubes

AbstractHemispherical polyarenes represent attractive templates from which carbon nanotubes of the same diameter and rim structure (chirality) might be grown by repetitive annulation reactions. The resulting single-index (n,m) nanotubes would have one end open and the other end capped by the original template. Efforts in the author’s laboratory to synthesize (5,5) and (6,6) nanotube end-caps are described. Nitroethylene is shown to serve well as a “masked acetylene” for the conversion of polyarene bay regions into new unsubstituted benzene rings by a Diels-Alder cycloaddition/aromatization process. Benzyne reacts similarly, both in solution and in the gas phase. These annulation reactions are proposed as methods for elongating large-diameter templates that have bay regions on their rims into structurally uniform, single-walled carbon nanotubes. Unfortunately, the bay regions on the strongly curved rim of the small-diameter (5,5) nanotube end-cap 3 resist Diels-Alder cycloadditions with both nitroethylene and benzyne. Pentabenzocorannulene (14) is proposed as a promising candidate for surface-catalyzed cyclodehydrogenation to a surface-bound hemispherical polyarene that could serve as a template for synthesis of pure (5,5) carbon nanotubes.

Download Full-text