|
|
Optical setup for torque detected electron spin resonance spectroscopy
Kern, Michal ; Vetushka, Aliaksei (referee) ; Neugebauer, Petr (advisor)
Táto diplomová práca sa venuje vylepšeniu spektroskopu Torzne Detegovanej Elektrónovej Spinovej Rezonancie (TDESR) výmenou aktuálnej kapacitnej detekcie výchylky ohybného ramienka za optické metódy. Práca popisuje základy Elektrónovej Spinovej Rezonančnej (ESR) spektroskopie s dôrazom na TDESR a tému magnetizmu jednomolekulových magnetov. Následne je vysvetlená detekcia výchylky ramienka pomocou odrazu laserového zväzku a interferometrie. Všetky kroky nutné k skonštruovaniu spektrometra a jeho uvedenia do prevádzky sú podrobne popísané. Pomocou detekcie odrazu laserového zväzku sme úspešne získali vysoko kvalitné TDESR spektrá kryštálu jednomolekulového magnetu Fe4. Týmto meraním sme dokázali vhodnosť použitia tejto metódy a jej výraznú prevahu nad pôvodnou kapacitnou detekciou, najmä v oblasti kvality, rozlíšenia a rýchlosti. Zároveň sme na ďaľšie vylepšenie TDESR spektrometra navrhli a zostrojili zostavu využívajúcu na detekciu výchylky interferometer.
|
|
|
Design of single-crystal sample holder for high-frequency electron paramagnetic resonance
Gabriš, Andrej ; Kern, Michal (referee) ; Sojka, Antonín (advisor)
This bachelor's thesis discusses the design and manufacture of non-resonant sample holder for the study of oriented crystals, which is used for high-frequency electron paramagnetic resonance (HF-EPR). The first part of the thesis is a theoretical introduction to EPR with the application of high frequency (80-1100 GHz) and high magnetic field (16 T). This work further analyzes the topic of crystal samples anisotropy and introduces the review of materials suitable for a sample holder, which is used in low-temperature conditions (4 K). The practical part of the thesis deals with the constructional design of the rotary sample holder. This section also compares the manufacturing possiblities of the selected parts of the sample holder: machining (milling and turning) and 3D printing. Lastly, this work describes the development of the user interface for automatization of an EPR spectrum measurement.
|
|
|
Optimization of the radiofrequency atomic source for deposition of GaN
Kern, Michal ; Wertheimer, Pavel (referee) ; Mach, Jindřich (advisor)
This thesis is focused on construction and optimization of radiofrequency atomic dissociation source of atomic nitrogen for depostion of GaN. The theoretical part deals with atomic sources, growth of ultrathin layers and the issue of radiofrequency circuits, with emphasis on their design using Smith chart. Methods for synthesis of GaN ultrathin layers and deposition are also discussed. In the experimental part, design and realization of various congurations of the impedance matching network is described. Using the impedance matching network a nitrogen plasma discharge was successfuly created and its spectrum was analysed. Afterwards, design and realization of a stepper motor control for the impedance matching network is described.
|
|
|
Design of single-crystal sample holder for high-frequency electron paramagnetic resonance
Gabriš, Andrej ; Kern, Michal (referee) ; Sojka, Antonín (advisor)
This bachelor's thesis discusses the design and manufacture of non-resonant sample holder for the study of oriented crystals, which is used for high-frequency electron paramagnetic resonance (HF-EPR). The first part of the thesis is a theoretical introduction to EPR with the application of high frequency (80-1100 GHz) and high magnetic field (16 T). This work further analyzes the topic of crystal samples anisotropy and introduces the review of materials suitable for a sample holder, which is used in low-temperature conditions (4 K). The practical part of the thesis deals with the constructional design of the rotary sample holder. This section also compares the manufacturing possiblities of the selected parts of the sample holder: machining (milling and turning) and 3D printing. Lastly, this work describes the development of the user interface for automatization of an EPR spectrum measurement.
|
|
|
Optical setup for torque detected electron spin resonance spectroscopy
Kern, Michal ; Vetushka, Aliaksei (referee) ; Neugebauer, Petr (advisor)
Táto diplomová práca sa venuje vylepšeniu spektroskopu Torzne Detegovanej Elektrónovej Spinovej Rezonancie (TDESR) výmenou aktuálnej kapacitnej detekcie výchylky ohybného ramienka za optické metódy. Práca popisuje základy Elektrónovej Spinovej Rezonančnej (ESR) spektroskopie s dôrazom na TDESR a tému magnetizmu jednomolekulových magnetov. Následne je vysvetlená detekcia výchylky ramienka pomocou odrazu laserového zväzku a interferometrie. Všetky kroky nutné k skonštruovaniu spektrometra a jeho uvedenia do prevádzky sú podrobne popísané. Pomocou detekcie odrazu laserového zväzku sme úspešne získali vysoko kvalitné TDESR spektrá kryštálu jednomolekulového magnetu Fe4. Týmto meraním sme dokázali vhodnosť použitia tejto metódy a jej výraznú prevahu nad pôvodnou kapacitnou detekciou, najmä v oblasti kvality, rozlíšenia a rýchlosti. Zároveň sme na ďaľšie vylepšenie TDESR spektrometra navrhli a zostrojili zostavu využívajúcu na detekciu výchylky interferometer.
|
|
|
Optimization of the radiofrequency atomic source for deposition of GaN
Kern, Michal ; Wertheimer, Pavel (referee) ; Mach, Jindřich (advisor)
This thesis is focused on construction and optimization of radiofrequency atomic dissociation source of atomic nitrogen for depostion of GaN. The theoretical part deals with atomic sources, growth of ultrathin layers and the issue of radiofrequency circuits, with emphasis on their design using Smith chart. Methods for synthesis of GaN ultrathin layers and deposition are also discussed. In the experimental part, design and realization of various congurations of the impedance matching network is described. Using the impedance matching network a nitrogen plasma discharge was successfuly created and its spectrum was analysed. Afterwards, design and realization of a stepper motor control for the impedance matching network is described.
|
|
| |
|
| |
|
| |
guest ::
