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Properties study of periodic gratings prepared by electron-beam lithography
Krátký, Stanislav ; Opletal, Petr (referee) ; Matějka, Milan (advisor)
This study examines the process of the relief periodic structures creation by way of electron beam lithography. It describes how to design these structures by means of a computer and subsequently how to create them by electron beam lithograph. Moreover, this study explores the methods by which these structures are measured and evaluated. These methods are used to measure and evaulate binary periodic gratings and thanks to obtained data it can be determined the dependence of the depth of grating on its period. The study also contains measurement of diffraction efficiency on manufactured gratings and comparison of the dependence of its diffraction efficiency on the depth of grating.
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Map Creation Environment using OpenStreetMap Project Data
Opletal, Petr ; Rozman, Jaroslav (referee) ; Novotný, Tomáš (advisor)
This bachelor's thesis deals with the development of environment for creating maps using OpenStreetMap vector data. The final application allows to change appearance of maps and to import data from external sources (e.g. own tracks). The text contains a theoretical introduction, the information about the OpenStreetMap project and the information about the Google My Tracks application. Further, this text deals with the application design, implementation and testing. The conclusion summarizes achieved results and suggests some proposals how to extend the application.
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Golf Ball Flight Simulation and Visualization
Opletal, Petr ; Beran, Vítězslav (referee) ; Španěl, Michal (advisor)
This diploma thesis deals with the simulation and vizualization of a golf ball flight. The final application is powered by the Unity engine and the PhysX physics library. The application includes the implementation of basic golf ball aerodynamics and advanced vizualization including simple gaming logic. The final solution can be used as a part of a cheap golf simulator. The text contains a theoretical introduction, existing solutions, basics of golf ball aerodynamics, an application design, the creation of courses and implementations. The conclusion of the diploma thesis describes experiments with the final solution and summarizes the achieved results.
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Studium magnetických kvantově kritických jevů na uranových sloučeninách
Opletal, Petr ; Pospíšil, Jiří (advisor) ; Javorský, Pavel (referee)
Motivation of this thesis is a study of magnetic phase diagram of the pseu- doternary system UCoxRu1−xAl. Three single crystals UCo0.19Ru0.81Al, UCo0.27Ru0.73Al and UCo0.40Ru0.60Al have been successfully prepared by Czochralski method. Composition was confirmed by EDX analysis and quality of single crystals was checked by Laue method. Crystallographic parameters and occupancies were de- termined by X-ray powder diffraction. Data analysis confirmed strong uniaxial magnetocrystalline anisotropy (c is the easy magnetization axis) and existence of hard and soft ferromagnetic phase. Curie temperature TC = 41 K was determined for UCo0.40Ru0.60Al and phase transition from the soft ferromagnetic phase to the hard one takes place at 35 K. UCo0.27Ru0.73Al becomes ferromagnetic at TC = 18 K and the transition from the soft to the hard ferromagnetic phase takes place somewhere around 7 K. UCo0.19Ru0.81Al is paramagnetic down to 2 K. Analysis of the temperature dependence of resistivity and heat capacity reveals signatures of non-Fermi liquid behaviour due to proximity of quantum critical point. 1
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Kritické chování v magnetických fázových diagramech uranových sloučenin
Opletal, Petr ; Prokleška, Jan (advisor)
Title: Critical behavior in magnetic phase diagrams of uranium compounds Author: Bc. Petr Opletal Department: Department of Condensed Matter Physics Supervisor: RNDr. Jan Prokleška, Ph.D., Department of Condensed Matter Physics Abstract: This work is focused on study of phase diagrams and related critical effects in the pseudoternary UCo1-xRuxAl compound. Three single crystals of nominal composition UCo0.99Ru0.01Al, UCo0.995Ru0.005Al and UCo0.9975Ru0.0025Al have been prepared by Czochralski method in triarc furnace. Quality of single crystals was checked by EDX analysis, Laue method and XRPD. For UCo0.99Ru0.01Al Curie temperature was determined as TC = 16 K. UCo0.995Ru0.005Al shows transition from paramagnetic to ferromagnetic phase at TC= 4.5 K and at higher temperatures we observe a metamagnetic transition of first order with a critical field HC = 0.04 T. UCo0.9975Ru0.0025Al is paramagnetic to low temperatures with metamagnetic transition of first order and critical field HC = 0.55 T. Experiments in hydrostatic pressure on UCo0.995Ru0.005Al and UCo0.9975Ru0.0025Al showed decay of ferromagnetism and increase of critical field. This behavior is similar to evolution of magnetism in UCoAl and URhAl in applied hydrostatic pressure. Keywords: UCoAl, URuAl, ferromagnetism, metamagnetism
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Peculiarities of magnetism on the verge of ferromagnetic ordering
Opletal, Petr ; Prokleška, Jan (advisor) ; Nhu-Tarnawska, Hoa Kim Ngan (referee) ; Veis, Martin (referee)
This thesis focuses on the study of magnetic properties of three 5f electron itinerant ferromagnets UCo0.990Ru0.010Al, UCoGa and URhGa and investigation of their phase diagrams. The single crystals of high-quality were prepared by Czochralski method for all three compounds. The physical properties at ambient pressure were studied by macroscopic methods (magnetization, electrical transport and heat capacity measurements) and also by magnetic force microscopy (MFM). The measurements were done under various external conditions (high pressure, low temperatures, high magnetic field). Through all these measurements and external conditions we investigated the interesting physical properties and the ferromagnetic phase diagrams. Effect of different conditions during the preparation and the thermal treatment on UCoGa was studied on two different single crystals. We show that annealing leads to improved quality of samples and the gallium evaporation from the melt during the growth leads to lower quality in parts of the ingot closer to melt. MFM images of UCoGa below the ordering temperature show domain branching and narrow magnetic domains wall made only of neighboring atoms with opposing moments. We have grown first ever single crystal of URhGa with ferromagnetic ordering temperature TC = 41 K. Anomalous maximum in...
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Kritické chování v magnetických fázových diagramech uranových sloučenin
Opletal, Petr ; Prokleška, Jan (advisor)
Title: Critical behavior in magnetic phase diagrams of uranium compounds Author: Bc. Petr Opletal Department: Department of Condensed Matter Physics Supervisor: RNDr. Jan Prokleška, Ph.D., Department of Condensed Matter Physics Abstract: This work is focused on study of phase diagrams and related critical effects in the pseudoternary UCo1-xRuxAl compound. Three single crystals of nominal composition UCo0.99Ru0.01Al, UCo0.995Ru0.005Al and UCo0.9975Ru0.0025Al have been prepared by Czochralski method in triarc furnace. Quality of single crystals was checked by EDX analysis, Laue method and XRPD. For UCo0.99Ru0.01Al Curie temperature was determined as TC = 16 K. UCo0.995Ru0.005Al shows transition from paramagnetic to ferromagnetic phase at TC= 4.5 K and at higher temperatures we observe a metamagnetic transition of first order with a critical field HC = 0.04 T. UCo0.9975Ru0.0025Al is paramagnetic to low temperatures with metamagnetic transition of first order and critical field HC = 0.55 T. Experiments in hydrostatic pressure on UCo0.995Ru0.005Al and UCo0.9975Ru0.0025Al showed decay of ferromagnetism and increase of critical field. This behavior is similar to evolution of magnetism in UCoAl and URhAl in applied hydrostatic pressure. Keywords: UCoAl, URuAl, ferromagnetism, metamagnetism
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Kritické chování v magnetických fázových diagramech uranových sloučenin
Opletal, Petr ; Prokleška, Jan (advisor) ; Havela, Ladislav (referee)
Title: Critical behavior in magnetic phase diagrams of uranium compounds Author: Bc. Petr Opletal Department: Department of Condensed Matter Physics Supervisor: RNDr. Jan Prokleška, Ph.D., Department of Condensed Matter Physics Abstract: This work is focused on study of phase diagrams and related critical effects in the pseudoternary UCo1-xRuxAl compound. Three single crystals of nominal composition UCo0.99Ru0.01Al, UCo0.995Ru0.005Al and UCo0.9975Ru0.0025Al have been prepared by Czochralski method in triarc furnace. Quality of single crystals was checked by EDX analysis, Laue method and XRPD. For UCo0.99Ru0.01Al Curie temperature was determined as TC = 16 K. UCo0.995Ru0.005Al shows transition from paramagnetic to ferromagnetic phase at TC= 4.5 K and at higher temperatures we observe a metamagnetic transition of first order with a critical field HC = 0.04 T. UCo0.9975Ru0.0025Al is paramagnetic to low temperatures with metamagnetic transition of first order and critical field HC = 0.55 T. Experiments in hydrostatic pressure on UCo0.995Ru0.005Al and UCo0.9975Ru0.0025Al showed decay of ferromagnetism and increase of critical field. This behavior is similar to evolution of magnetism in UCoAl and URhAl in applied hydrostatic pressure. Keywords: UCoAl, URuAl, ferromagnetism, metamagnetism
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Studium magnetických kvantově kritických jevů na uranových sloučeninách
Opletal, Petr ; Pospíšil, Jiří (advisor) ; Javorský, Pavel (referee)
Motivation of this thesis is a study of magnetic phase diagram of the pseu- doternary system UCoxRu1−xAl. Three single crystals UCo0.19Ru0.81Al, UCo0.27Ru0.73Al and UCo0.40Ru0.60Al have been successfully prepared by Czochralski method. Composition was confirmed by EDX analysis and quality of single crystals was checked by Laue method. Crystallographic parameters and occupancies were de- termined by X-ray powder diffraction. Data analysis confirmed strong uniaxial magnetocrystalline anisotropy (c is the easy magnetization axis) and existence of hard and soft ferromagnetic phase. Curie temperature TC = 41 K was determined for UCo0.40Ru0.60Al and phase transition from the soft ferromagnetic phase to the hard one takes place at 35 K. UCo0.27Ru0.73Al becomes ferromagnetic at TC = 18 K and the transition from the soft to the hard ferromagnetic phase takes place somewhere around 7 K. UCo0.19Ru0.81Al is paramagnetic down to 2 K. Analysis of the temperature dependence of resistivity and heat capacity reveals signatures of non-Fermi liquid behaviour due to proximity of quantum critical point. 1
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Golf Ball Flight Simulation and Visualization
Opletal, Petr ; Beran, Vítězslav (referee) ; Španěl, Michal (advisor)
This diploma thesis deals with the simulation and vizualization of a golf ball flight. The final application is powered by the Unity engine and the PhysX physics library. The application includes the implementation of basic golf ball aerodynamics and advanced vizualization including simple gaming logic. The final solution can be used as a part of a cheap golf simulator. The text contains a theoretical introduction, existing solutions, basics of golf ball aerodynamics, an application design, the creation of courses and implementations. The conclusion of the diploma thesis describes experiments with the final solution and summarizes the achieved results.
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