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Epitaxial growth of cobalt islands via oxide mediated epitaxy
Stará, Veronika ; Kolíbal, Miroslav (referee) ; Čechal, Jan (advisor)
This bachelor thesis deals with preparation, growth and analysis of cobalt thin films. The films are formed on silicon (111) samples covered with a thin layer of native oxide SiO2. Cobalt thin films were prepared using oxide mediated epitaxy method with the effusion cell as a source of cobalt atoms. Composition and morphology of the resulting Co system was studied as a function of the annealing temperature. Another goal of this research was to determine the dependence of the final island shape on the amount of deposited material and substrate orientation. The prepared structures were analyzed using X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. To determine the thickness of subsurface islands the samples were etched in buffered hydrofluoric acid and analyzed using above mentioned methods.
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Design of manipulator for ultrahigh electron microscope
Caesar, Radek ; Mach, Jindřich (referee) ; Bábor, Petr (advisor)
The main purpose of this thesis is mechanical design of a manipulator for an ultra-high vacuum scanning electron microscope (UHV SEM), being currently developed by TESCAN ORSAY HOLDING a.s. in cooperation with the Institute of physical engineering FME BUT. The manipulator is supposed to be able to handle with specimens in so-called preparation chamber, which the specimens are put in before placing into the analytic chamber. In the preparation chamber the surface finishing and also other operations are made. In the theoretical part some of the technologies used in vacuum engineering, especially various principles of pressure measurement and gas pumping, are described. Besides, the thesis is focused on a brief description of UHV SEM being developed and the methods of specimen preparation. The practical part deals with the concept and the mechanical design of manipulator itself.
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Design of the supporting platform for low temperature UHV STM microscope
Dao, Tomáš ; Křupka, Ivan (referee) ; Pavera, Michal (advisor)
Diploma thesis deals with the design of a vibration isolated platform for low temperature scanning tunneling microscope working under ultra high vacuum (UHV STM). Cooling of the microscope is done by liquid helium using a flow cryostat designed in Institute of Scientific Instruments of the AS CR. In the thesis, general requirements of designing of an ultra high vacuum compatible devices are discussed, as well as the ways of vibrational isolation and damping. Also some ways how to restrict the transfer of vibration between vacuum devices and surroundings are mentioned. This knowledge is then applied to the design of the antivibrational microscope platform compatible with low temperature usage. For better understanding of vibrational transfer and damping, a real model of the designed platform is made and vibrational transfer characteristics are measured and compared with the theory.
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Design of manipulator for ultrahigh electron microscope
Caesar, Radek ; Mach, Jindřich (referee) ; Bábor, Petr (advisor)
The main purpose of this thesis is mechanical design of a manipulator for an ultra-high vacuum scanning electron microscope (UHV SEM), being currently developed by TESCAN ORSAY HOLDING a.s. in cooperation with the Institute of physical engineering FME BUT. The manipulator is supposed to be able to handle with specimens in so-called preparation chamber, which the specimens are put in before placing into the analytic chamber. In the preparation chamber the surface finishing and also other operations are made. In the theoretical part some of the technologies used in vacuum engineering, especially various principles of pressure measurement and gas pumping, are described. Besides, the thesis is focused on a brief description of UHV SEM being developed and the methods of specimen preparation. The practical part deals with the concept and the mechanical design of manipulator itself.
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|
|
Epitaxial growth of cobalt islands via oxide mediated epitaxy
Stará, Veronika ; Kolíbal, Miroslav (referee) ; Čechal, Jan (advisor)
This bachelor thesis deals with preparation, growth and analysis of cobalt thin films. The films are formed on silicon (111) samples covered with a thin layer of native oxide SiO2. Cobalt thin films were prepared using oxide mediated epitaxy method with the effusion cell as a source of cobalt atoms. Composition and morphology of the resulting Co system was studied as a function of the annealing temperature. Another goal of this research was to determine the dependence of the final island shape on the amount of deposited material and substrate orientation. The prepared structures were analyzed using X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. To determine the thickness of subsurface islands the samples were etched in buffered hydrofluoric acid and analyzed using above mentioned methods.
|
|
|
Design of the supporting platform for low temperature UHV STM microscope
Dao, Tomáš ; Křupka, Ivan (referee) ; Pavera, Michal (advisor)
Diploma thesis deals with the design of a vibration isolated platform for low temperature scanning tunneling microscope working under ultra high vacuum (UHV STM). Cooling of the microscope is done by liquid helium using a flow cryostat designed in Institute of Scientific Instruments of the AS CR. In the thesis, general requirements of designing of an ultra high vacuum compatible devices are discussed, as well as the ways of vibrational isolation and damping. Also some ways how to restrict the transfer of vibration between vacuum devices and surroundings are mentioned. This knowledge is then applied to the design of the antivibrational microscope platform compatible with low temperature usage. For better understanding of vibrational transfer and damping, a real model of the designed platform is made and vibrational transfer characteristics are measured and compared with the theory.
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