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A method for the solution of non-spherical (fiber) particles deposition by means of the Fokker-Planck equation for ODF in a laminar flow
Kopečková, Barbora ; Knotek, Stanislav (referee) ; Jícha, Miroslav (advisor)
The Bachelor's thesis deals with a deposition efficiency for a fibers by various mechanisms of a deposition. It explains deposition efficiency by diffusion, by sedimentation and by impaction. The implementation of Peterlin's analytical solution for calculation of the ODF, which is used for individual efficiencies solution, is also mentioned. Afterwards, the thesis summarizes formulas for calculation of particular efficiencies derived for spherical particles and recomputation appropriate parameters for fibers. The purpose of the thesis is to create graphs, which illustrate deposition efficiencies dependence by various mechanisms on the aspect ratio of fibers. Another goal is the graphs creation, which shows juxtaposition for various breathing modes for given deposition mechanisms. The software MATLAB is used for the whole calculation process and graphs plotting.
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Deposition of magnetic nanostructures using EBID and optimalization of their chemical composition and morphology
Vyroubal, Ondřej ; Kolíbalová, Eva (referee) ; Kolíbal, Miroslav (advisor)
This master's thesis deals with deposition of cobalt nanostructures using Electron Beam Induced Depositon (EBID). The thesis firstly describes theoretical background regarding EBID. In the following experimental part, the deposition process is optimized via analysis of exposition parameters and their influence on the final shape of nanostructures. These are analyzed via Atomic Force Microscopy (AFM). Optimized exposure parameters are then applied to the deposition of functional 3-dimensional nanostrucutres. In particular, the deposition of cobalt spheres. The elemental composition is analyzed by the means of element composition using Energy-dispersive X-ray Spectroscopy (EDX) and the nanostructures of desired morphologies are studied with Magnetic Force Microscopy (MFM) and Magneto-Optical Kerr Microscope).
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Evaluation of the use of cold kinetic deposition technology on materials used in electrical engineering
Šteiniger, Jakub ; Zimáková, Jana (referee) ; Binar, Tomáš (advisor)
The master´s thesis deals with a process called cold kinetic deposition technology. Using this technology, a copper layer was formed on a sample with an aluminium base by high-pressure cold spraying at a pressure of 25 bar. In the experimental part, the influence of corrosion degradation in the salt chamber was assessed at the time cycles of 100 h, 200 h and 300h, where changes in internal and surface resistances before and after corrosion were measured. Subsequently, the analysis of corrosion products was performed, where the extent of corrosion attack was determined using an electron microscope. These methods led to a final evaluation of the boundary limits of the applied coating layer by cold kinetic deposition, after the effect of corrosion. Finally, a theoretical application of this technology was suggested. It was discovered that the sample placed and left in the corrosion chamber for the longest time was the most affected by corrosion. Finally, a theoretical application of cold kinetic deposition was proposed.
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SiO2 etching by Si deposition
Pokorný, David ; Bábor, Petr (referee) ; Polčák, Josef (advisor)
This bachelor thesis deals with one of the most interesting reactions taking place in the solid phase in UHV conditions and that is decomposition of SiO2 according to the equation Si + SiO2 = 2SiO. It was used the previously untested procedure - providing Si atoms not from substrate, but by direct deposition on the surface of the oxide. As a source of silicon atoms was used effusion cell. Deposition of silicon on SiO2 substrate was used at room temperature and at elevated temperature to clarify the principle of this reaction. The activation energy and temperature dependence of the reaction rate was determined. It was also verified the possibility of etching SiO2 by Si deposition in UHV conditions. The prepared samples were examined by x-ray photoelectron spectroscopy and atomic force microscopy.
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Thin film systems
Rada, Vojtěch ; Sedlaříková, Marie (referee) ; Zatloukal, Miroslav (advisor)
This bachelor’s thesis is focused on the problematics of thin-film technology. In the beginning the work deals with a general theory of this problematics, discusses various methods and ways to lay a thin film, where more emphasis is placed on magnetron sputtering, which is used in the practical part of the work, and describes procedures that are performed before and after the application of the thin film. The magnetron sputtering coating machine NP-12 and its control are described in the practical part of the work. Subsequently the selection and adjustment of suitable substrates is made, the thin-film system is deposited using the magnetron sputtering method and the analysis of the properties of deposited thin-film samples is done.
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Vizualization of flow of fibers from insulation mineral wool
Kedajová, Kristýna ; Elcner, Jakub (referee) ; Lízal, František (advisor)
One of the most used insulation materials of our time is mineral wool. As with formerly used asbestos, not all the health impacts of mineral wool fibers inhalation are known. The aim of this thesis is to gather findings relating to the transport of aerosols, their deposition in human airways and to obtain and statistically evaluate experimental data from the visualization of fibres in the glass tube resembling human airways. This data can improve understanding of the relation between glass fibres action and possible health hazard.
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Studies of molecular beams of organic materials
Maniš, Jaroslav ; Průša, Stanislav (referee) ; Mach, Jindřich (advisor)
This bachelor's thesis deals with assembling of low-temperature efussion cell which is suitable for deposition of organic materials. The calibration of operating temperature of effusion cell is performed. Depositions of organic semiconductor material are realized. Morphology of surface of thin film is studied in AFM and SEM microscope. In the paper background research on the utilization of organic materials in semiconductor industry is presented.
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Tools Made from Cemented Carbide
Opršál, Ladislav ; Osička, Karel (referee) ; Kalivoda, Milan (advisor)
The thesis focuses on cutting tools made of both coated and uncoated cemented carbides. The first part of the thesis deals with the division of materials used for the production of the tools. The second part of the thesis introduces uncoated cemented carbides, special attention being paid to the labelling, production and properties of such compounds. The third part of the thesis presents coating deposition techniques and examines the properties of coating layers. Coating layers are produced using two different methods – CVD and PVD. The last part of the thesis compares the properties of the cutting tools (e.g. their cutting values) produced by the companies Pramet Tools, Sandvik – Coromant and Seco Tools.
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