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Preparation and testing of SNOM probes
Bobek, Juraj ; Pavera, Michal (referee) ; Spousta, Jiří (advisor)
The area of research that deals with surface modification and preparation of nanostructures is still very unexplored. And only a little contribution to this field is discussed in this bachelor thesis. Its goal is to manufacture and to test a probe made off hollow optical fibre that is used in Scanning Probe Microscopy. Optical fibre parameters in combination with proper and unique techniques allow the breakthrough off very interesting applications. It's worth mentioning the gas injection in the proximity of the surface of a sample (GIS) and thus its modification by use of electrons (FEBID), ions (FIBID) or laser beams.
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Automation and control of multilayers deposition by IBS/IBAD
Pavera, Michal ; Sobota, Jaroslav (referee) ; Urbánek, Michal (advisor)
This diploma thesis deals with the automation of the deposition process by ion beam sputtering and ion beam assisted deposition. This work contains drawings of mechanical adjustments of the deposition chamber designed to control shutter and rotation of the target using stepper motors. There are presented ways to control stepper motors and troubleshoot their exact settings. Another task is to design a system for computer control of the deposition process. There are discussed ways to control the ion sources, pressure meter, flow meter and thickness meter, and their connection to a PC via RS-232 and analog-digital converters. It is also designed control program in LabVIEW, which allow automated multilayer deposition. Last part of the thesis deals with testing automatic deposition and results are commented.
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Design and optimization of piezoactuators
Jajtner, Jan ; Pavera, Michal (referee) ; Nováček, Zdeněk (advisor)
This bachelor’s thesis main concern is to develop and optimize a linear impact-drive piezoelectric actuator for scanning tunneling microscope working as vertical macroscopic manipulator of the conducting tip. UHV piezoelectric actuator issues are being discussed and analyzed on theoretical level in order to create adequate mathematical model. Based on expressed requirements a prototype is designed and measured, while seeking appropriate parameters of supply pulse and loading.
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Mechanical excitation of self sensing SPM probes
Novotný, Ondřej ; Piastek, Jakub (referee) ; Pavera, Michal (advisor)
This bachelor thesis deals with the development of the SPM microscope probe holder which is designed for mechanical excitation of the probes. The first part of the thesis focuses on the description of physical theory, such as the principle of atomic force microscopy, the function of piezoceramics and the description of used quartz tunning fork based probes. The second part describes the gradual development and design of the new probe holder. Testing of the designed probe holder and comparison of mechanical and electric excitation is depicted at the end of this work. The designed probe holder was manufactured, the assembly procedure was described, and the drawings of the individual parts were created.
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Assembling and testing of low temperature STM microscope
Sojka, Antonín ; Páleníček, Michal (referee) ; Pavera, Michal (advisor)
This bachelor thesis addresses the problem of assebling the low temperature STM working in ultrahigh vacuum. The thesis deals with connecting the microscope and electronics. The desing of temperature stabilizers for fixing the low temperatures is described along with a construction of expanding the vacuum chamber to test STM in low temperatures. The thesis describes the construction of sample and tip holders to insert samples and tips into the STM. At the end there are brief instructions to use GXSM software and testing the microscope in atmospheric pressure.
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Advanced SPM techniques for measuring electrical properties of materials
Kramář, Jan ; Konečný, Martin (referee) ; Pavera, Michal (advisor)
This bachelor thesis is concerned about development of local electric properties characterization technique of sample in contact mode of Atomic Force Microscopy. The research part describes the most expanded techniques of characterization of local electric properties using Scanning Probe Microscopy. For realization was chosen Scanning Spreading Resistance Microscopy. Important part of this technique is current amplifier. For that reason, operational amplifiers, circuits with them and implementation of new amplifier on microscop are described. Last chapter is dedicated to description of samples, which were used to test functionality of the amplifier and technique.
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Real-time study of reaction waves
Gazdík, Richard ; Pavera, Michal (referee) ; Bábor, Petr (advisor)
Táto bakalárska práca sa zaoberá heterogénnou katalytickou oxidáciou oxidu uhoľnatého, a hlavne reakčnými vlnami vyskytujúcimi sa pri určitých podmienkach, na povrchu platiny. Práca je rozdelená na dve hlavné časti – teoretickú a experimentálnu. Teoretická časť podáva informácie ohľadom rastrovacieho elektrónového mikroskopu, mikroskopu atomárnych síl a detailov reakcie. Pre experimentálnu časť boli vykonané pozorovania tejto reakcie v ultravysoko-vákuovom, ako aj vo vysoko-vákuovom rastrovacom elektrónovom mikroskope, a v oboch prípadoch boli identifikované reakčné vlny. Cieľom bolo tiež skúsiť vykonať korelatívne meranie reakčných vĺn sondou a elektrónovým mikroskopom (CPEM), ktoré, bohužiaľ, z veľa rôznych dôvodov popísaných v poslednej časti práce, nevyšlo.
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Correlated probe and electron microscopy for the study of modern magnetic nanomaterials
Novotný, Ondřej ; Flajšman, Lukáš (referee) ; Pavera, Michal (advisor)
High pressure on the development of new magnetic materials and their miniaturization also emphasizes the development of new analytical techniques. This diploma thesis deals with the development and demonstration of correlated magnetic force and electron microscopy, which is a promising tool for the characterization of magnetic nanomaterials. The first part of this thesis describes the fundamental physics of micromagnetism with a focus on cylindrical nanofibers. The following pages describe optic, probe, electron, and synchrotron methods for mapping the magnetic properties of materials. The next part describes magnetic domain wall motion in cylindrical nanowires performed as a part of a more extensive material study. The last part of the thesis describes the development of correlated magnetic force and electron microscopy on LiteScope device. A production of magnetic probes was designed and successfully tested. Probes were fabricated by focused electron beam-induced deposition from the Co2(CO)8 precursor. Further, the developed correlated microscopy is demonstrated on a multilayer PtCo sample, magnetic cylindrical nanofibers, NiFe vortex structures, and FeRh metamagnetic nano-islands.
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Local electrical conductivity measurements in AFM tapping mode
Dao, Radek ; Konečný, Martin (referee) ; Pavera, Michal (advisor)
This bachelor thesis is concerned about the development of a probe for local electrical conductivity measurements in tapping mode Atomic Force Microscopy. The teoretical part gives a short overview of Scanning Probe Microscopy techniques, with the focus being on Conductivity Atomic Force Microscopy. Furthermore, the measuring regime in which the probe operates is described here, as well as the basic component of the probe, the quartz tuning fork. The experimental part follows the iterative development process, and contains a chapter dedicated to making of very sharp tips. The final chapters describe the preparation of test samples, which were used to prove the functionality of the probe and the measurement of local electrical conductivity itself.
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Design of Low-Temperature Ultra High Vacuum Scanning Probe Microscopes
Pavera, Michal ; Klapetek, Petr (referee) ; Vetushka, Aliaksei (referee) ; Šikola, Tomáš (advisor)
This thesis deals with the development of scanning probe microscopes. Mechanical requirements for microscopes using measuring methods of scanning tunneling microscopy (STM) and atomic force microscopy (AFM) under enviroments of an ultrahigh vacuum (UHV) and variable temperatures are specified. Mechanical designs of two microscopes are discussed and their control electronics described. A special chapter is devoted to description of linear piezo manipulators and mechanical design of these prototypes.
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