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Local oxidation of graphene using atomic force microscopy
Vymazal, Jan ; Špaček, Ondřej (referee) ; Bartošík, Miroslav (advisor)
This bachelor’s thesis aims to local anodic oxidation (LAO) using atomic force microscopy. Local anodic oxidation appers like promising method for preparing prototypes of graphene nanostructures. It may be utilised in fabrication of nanoelectronics, biosensors or Hall pro bes. Modified graphene is studied using atomic force microscopy (measuring topography, KPFM) and Raman spectroscopy. This work is studying influence of the loading force, number of layers and the substate on the result of LAO.
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Design of repair material with reduced electrical impedance
Žáková, Karolina ; Černý, Vít (referee) ; Drochytka, Rostislav (advisor)
This bachelor's thesis focuses on designing a new composition of corrective material based on silicate with the aim of reducing electrical impedance. In the theoretical part, fundamental concepts necessary for understanding the topic will be described, such as terms related to conductivity, silicates, composites, and corrective materials in general. The experimental section includes the selection of raw materials, preparation, and testing of various compositions of corrective materials with different fillers. The impact of various additives on the electrical properties of the corrective material will be investigated, including its conductivity, resistivity, and cohesion. The final section summarizes and evaluates the achieved results.
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Carbon materials for power sources
Tichý, Jiří ; Bača, Petr (referee) ; Novák, Vítězslav (advisor)
This work deals with carbon materials and using them in electrochemical energy sources. Object of this work was to prepare carbon materials and investigate their electrical properties. The theoretical part objects of the carbon materials, their properties, application in electrochemical energy sources and measurement methods used in experimental part. Experimental part describes the preparation of the electrodes with various carbon materials and summarizes the results of measurements.
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Frames of Tennis Rackets
Rajdlík, Lukáš ; Němec, Karel (referee) ; Molliková, Eva (advisor)
This bachelor’s thesis deals with materials used for manufacturing of the frame of tennis rackets. The thesis informs about the frame of tennis rackets development, from the origins of tennis to these days, when there are modern technologies used. There are parts of the frame of a tennis racket and construction requirements defined. There are two samples of tennis rackets investigated and the both samples are compared with each other.
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Natural Graphite as Negative Electrode Material for Lithium-Ion Batteries
Paulovics, Petr ; Jahn, Michal (referee) ; Libich, Jiří (advisor)
This bachelor thesis deals with an issue of lithium-ion batteries. It is focused on the negative (anode) electrode materials, dealing with the study of their electrochemical properties. The aim was to study the capacity characteristics of active electrode materials based on natural graphite. Mainly it was assessed the relationship morphology electrode material and the pressing pressure due to the electrochemical properties of the capacitive electrode. The first part of the thesis contains a theoretical introduction to the negative electrode materials with focuses on the composition and overall analysis of the lithium-ion cell. The second part is focuses on the manufacture, assembly and measurement of lithium-ion cells.
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XRD characterization of electrodes and electrode materials for electrochemical power sources
Klvač, Ondřej ; Chladil, Ladislav (referee) ; Čech, Ondřej (advisor)
The thesis describes available choices of methods for research of electrochemical power source electrode strcture by x-ray diffraction spectroscopy. At first there is a theoretical computation of difractogram. Then there are discussed possibilities of in-situ and ex-situ techniques as background research. Practical part of thesis compares theoretical assumptions to measurements of lithium and sodium cells, including analyze of crystallographic phases and lattice constants. As a conclusion, there are discussed possibilities of subsequent research.
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Low energy excitations in oriented graphite by THz magneto-optical spectroscopy
Dubský, Jan ; Kunc, Jan (referee) ; Vrba, Radimír (advisor)
This master’s thesis deals with the modelling of electronic properties of graphite crystal, which are measurable using a spectrometer based on high frequency electron paramagnetic resonance (HFEPR for short) located in laboratories of CEITEC BUT. This is especially the band structure of graphite and its Landau levels. The theoretical part of the thesis describes key effects and connections from quantum mechanics and definitions of important terms from solid state physics, which are used to describe the crystalline structure of graphite and its electronic properties. Furthermore, the project describes the HFEPR spectrometer and its functional principle. In the practical part of the thesis, there are numerical models of the band structure of graphite and of its Landau levels and description of the preparation of a graphite sample for measurement. At the end of the practical part there is the analysis of measurements results, namely the cyclotron resonance and Shubnikov-de Haas oscillations, thanks to which it is possible to determine physical parameters of the sample, such as effective mass of charge carriers and fundamental frequency.
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