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Functional Tungsten-based thin films and their characterization
Košelová, Zuzana ; Horáková, L. ; Sobola, Dinara ; Burda, Daniel ; Knápek, Alexandr ; Fohlerová, Z.
Anodizing is a technique by which thin oxide layers can be formed on a surface. Thin oxide layers have been found to be useful in a variety of applications, including emitters of electrons. Tungsten is still a common choice for cold field emitters in commercial microscopy applications. Its suitable quality can be further improved by thin film deposition. Not only the emission characteristic can be improved, but also the emitter operating time can be extended. Tungsten oxide is known for its excellent resistance to corrosion and chemical attack due to its stable crystal structure and strong chemical bonds between tungsten and oxygen atoms. Many techniques with different advantages and disadvantages have been used for this purpose. Anodization was chosen for this work because of the controllable uniform coverage of the material and its easy availability without the need for expensive complex equipment. The anodizing process involves applying an electrical potential to tungsten while it is immersed in an electrolyte solution. This creates a thin layer of tungsten oxide on the surface of the metal. The thickness and properties of the resulting oxide layer can be controlled by adjusting the anodization conditions, such as the electrolyte solution, voltage, and the duration of the process. In this work, H3PO4 was used as the electrolyte to test whether these tungsten oxide layers would be useful for electron emitters, for use in electron guns and other devices that require high-quality electron emitters. The properties were evaluated using appropriate techniques. In general, anodization of tungsten to form thin layers of tungsten oxide layers is a promising technique for producing high quality electron emitters.
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SMV-2023-06: Development of test specimens for SEM
Matějka, Milan ; Krátký, Stanislav ; Meluzín, Petr ; Košelová, Zuzana ; Chlumská, Jana ; Horáček, Miroslav ; Kolařík, Vladimír ; Knápek, Alexandr
The study focuses on the research and development of precise calibration samples featuring relief structures. These samples are designed for calibrating parameters in scanning electron microscopes (SEM). The testing patterns enable the verification and calibration of magnification, orthogonality, and geometric distortion. The preparation of calibration specimens utilizes micro lithographic techniques tailored for silicon processing and other relevant technological procedures.
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SMV-2023-05: DI2023
Matějka, Milan ; Krátký, Stanislav ; Meluzín, Petr ; Košelová, Zuzana ; Chlumská, Jana ; Horáček, Miroslav ; Kolařík, Vladimír ; Knápek, Alexandr
The research focuses on the investigation and development of precise calibration samples with relief structures. These samples are designed for calibrating parameters in scanning electron microscopes (SEM). Test patterns allow verification of the imaging quality through microscopic techniques such as overall magnification, field of view size, resolution, deformation in lateral axes, and other geometric distortions. Precision lithographic techniques and other methods derived from silicon processing technologies in the semiconductor industry are employed for sample preparation. The development has been directed towards optimizing the recording of etching masks before transferring the image onto a monocrystalline silicon substrate.
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Diffusion Behavior of Analyte Molecules in a Nanoporous Matrix Created from Polystyrene Nanoparticles
Košelová, Zuzana
This study investigates the diffusion behavior ofanalyte molecules in a nanoporous matrix of polystyrene particles.Two approaches, steady-state current and potential stepchronoamperometry were employed to calculate diffusioncoefficients and compare the effect of nanoporous matrices withdifferent diameter of pores and different method ofimmobilization of enzyme. Pores were created with close packingof polystyrene nanoparticles. The covalent and cross-linkingimmobilization were used to immobilize the enzyme.Chronoamperometric measurement was applied to detect analyte.The study found that the presence of nanoporous matricesimmobilized on p-lysine affects diffusion. The potential stepchronoamperometry method showed the improvement ofdiffusion. This study provides insight into the diffusion behaviorof analyte molecules in nanoporous matrices, which can be usefulin optimizing the design of amperometric biosensors.
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Verify the possibility of plasma treatment of printed circuit boards for subsequent surface treatment
Brokeš, Josef ; Košelová, Zuzana (referee) ; Otáhal, Alexandr (advisor)
This thesis deals with the regeneration and cleaning of printed circuit boards with emphasis on the use of plasma technology. Various surface cleaning methods, including manual cleaning, industrial washing and plasma treatment, were investigated and their effect on the subsequent quality of the paintwork. A systematic analysis of the effect of plasma treatment on the paint quality and functionality of the plates is also carried out, including an investigation of the possibility of regenerating older plates. This study provides a basis for further research and development in this area. The thesis also presents the design and implementation of a prototype plasma developer device for integration into a production line.
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