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Studium vlastností povrchových plazmonových polaritonů na magnetických materiálech / Study of Properties of Surface Plasmon Polaritons on Magnetic MaterialsDvořák, Petr January 2011 (has links)
The diploma thesis deals with the experimental study of surface plasmon polaritons (SPPs) on nano-structures with the Au/Co/Au multilayer. Plasmonic structures were prepared by the electron beam lithography and by the focused ion beam. A Scanning optical near-field microscope was used for detection of surface plasmon polaritons. SPPs were confirmed by the experiment with different polarizations of the illuminating light. Furthermore, differences in plasmon interference wavelengths was measured for different surface dielectric functions. Finally, the decantation of the SPPs interference image was measured in dependence on the external magnetic field.
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Posouzení vlastností heterogenních tupých svarů metodami svařování laserem a svazkem elektronů / Assessment of heterogeneous properties butt welds in laser welding and electron beam weldingRozsypal, Oldřich January 2015 (has links)
The project was developed within the engineering degree in engineering technology, and is focused in welding together of two different materials. Welds will be done on a high strength steel Domex 420 MC and deep drawing steel DC01 using laser welding, and will be compared with the method of electron beam welding. Part of this project is a scientific research describing the basic physical principles of both methods, different types of lasers, welding material properties and inspection of welds. In the experimental part was carried tensile test, macroscopic and microscopic examination. Finally, work is to evaluate the individual tests.
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Modifikace charakteru rozhraní substrát-nástřik vrstev deponovaných technologiemi žárového nanášení pomocí technologie elektronového paprsku / Modification of coating-substrate interface character of thermally sprayed coatings using electron beam technologyMareš, Jiří January 2015 (has links)
Tato práce je zaměřena na modifikaci charakteru rozhraní substrát-nástřik NiCrAlY povlaků nanesených pomocí technologie vodou stabilizované plazmy na substráty z oceli S235JRC+C. Přetavení žárové vrstvy elektronovým paprskem bylo zvoleno jako technologie pro modifikaci a dvě různé modifikace byly zkoumány. V práci byl proveden pokus o stanovení vlivu modifikací na adhezní vlastnosti nástřiku. Dále jsou v práci prezentovány analýzy mikrostruktury, fázového a chemického složení a mikrotvrdosti ve stavu před a po modifikaci. Během studie bylo zjištěno, že dochází ke změnám fázového složení jak během depozice, tak během modifikace elektronovým paprskem. Modifikace elektronovým paprskem způsobila roztavení oxidů původní mikrostruktury nástřiku, které následně rekrystalizovaly na povrchu modifikované vrstvy. Dalším získaným poznatkem bylo, že dochází ke snížení mikrotvrdosti po modifikaci, což bylo způsobeno odstraněním oxidů z mikrostruktury a promícháním materiálu substrátu a původního nástřiku. Adheze nástřiků v as sprayed stavu byla kvantifikována. V případě nástřiků modifikovaných elektronovým paprskem přesná kvantifikace nebyla možná, z důvodu předčasného porušení na rozhraní nástřik-adhezivní pojivo během adhezních testů.
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Aplikace grafénové membrány v nanoelektronických zařízeních / Application of Graphene Membrane in Nanoelectronic DevicesKormoš, Lukáš January 2015 (has links)
This diploma thesis is focused on the applications and fabrication of graphene membrane from graphene prepared by the chemical vapor deposition. Theoretical part deals with transport properties of the graphene and multiple scattering processes limiting the charge carrier mobility in this material. Included is short review of graphene membrane applications. Experimental part provides fabrication process for achieving suspended graphene device by utilizing electron beam lithography, focused ion beam, chemical etching and patterning of graphene. Graphene membrane is characterized by transport properties measurement and compared to non-suspended graphene.
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Elektrostatické vychylovací a korekční systémy / Electrostatic Deflection and Correction SystemsBadin, Viktor January 2015 (has links)
The aim of this master's thesis is to explore and study dynamic aberration correction options in electron-beam lithography systems. For the calculations, the thesis uses the optical column of the BS600 electron-beam writer. The thesis focuses on corrections of the third order field curvature, astigmatism, and distortion aberrations of the currently used magnetic deflection system and a newly designed electrostatic deflection system. The parameters of the two deflection and correction systems were compared.
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Selektivní růst GaN nanostruktur na křemíkových substrátech / Selective growth of GaN nanostructures on silicon substratesKnotek, Miroslav January 2015 (has links)
This thesis deals with deposition of gallium nitride thin films on silicon substrates covered by negative HSQ rezist. Rezist was patterned via electron beam lithography to create masks, where the selective growth of crystals was achieved. Growth of GaN layers was carried out by MBE method. For achievement of desired selective growth, the various deposition conditions were studied.
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Svařování ODS materiálů elektronovým svazkem / Electron beam welding of ODS materialsJankůj, Luděk January 2016 (has links)
Thesis on Electron beam welding of ODS materials is divided into theoretical and experimental part. In the first part the theoretical research work focuses on the accurate description of the candidate materials in a research fusion reactor ITER. Following are detailed constructional ODS materials and tungsten alloy as a material of the first wall. The second part of the theoretical research deals with various possibilities of joining high-melting dissimilar materials such as brazing or electron beam welding as well, which will be established in the experimental section. The experimental part of the thesis deals with a joining ODS steel MA 956 with sintered carbide WC-Co and ODS tungsten. These materials are welded by electron beam. Individual samples are distinguished used filler material, preheating or welding parameters. This thesis contains photographic documentations of microstructure the welding samples, results from scanning electron microscopy, and measurements of microhardness across the weld metal.
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Povrchové zpracování vybraných ocelí pomocí elektronového svazku / Surface treatment of selected steels using electron beamOríšek, Petr January 2016 (has links)
The thesis aims for the surface treatment of materials using electron beam. It includes a literary research describing physical principle and properties of the electron beam. This research also presents possible influencing of the beam and describes the construction of the device that generates the beam. Various applications of the electron beam for the material treatment are presented in the second part of the paper. Within this thesis an experiment with the heat treatment of the steel surface by the electron beam has been realized. The experiment was aimed at creating a layer as deep as possible without melting the surface. The results and their evaluation are presented in the experimental part of the thesis. The attention is also paid to selected process parameters.
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Electron-beam induced synthesis of nanostructures: a reviewGonzalez-Martinez, I. G., Bachmatiuk, A., Bezugly, V., Kunstmann, J., Gemming, T., Liu, Z., Cuniberti, G., Rümmeli, M. H. 16 December 2019 (has links)
As the success of nanostructures grows in modern society so does the importance of our ability to control their synthesis in precise manners, often with atomic precision as this can directly affect the final properties of the nanostructures. Hence it is crucial to have both deep insight, ideally with real-time temporal resolution, and precise control during the fabrication of nanomaterials. Transmission electron microscopy offers these attributes potentially providing atomic resolution with near real time temporal resolution. In addition, one can fabricate nanostructures in situ in a TEM. This can be achieved with the use of environmental electron microscopes and/or specialized specimen holders. A rather simpler and rapidly growing approach is to take advantage of the imaging electron beam as a tool for in situ reactions. This is possible because there is a wealth of electron specimen interactions, which, when implemented under controlled conditions, enable different approaches to fabricate nanostructures. Moreover, when using the electron beam to drive reactions no specialized specimen holders or peripheral equipment is required. This review is dedicated to explore the body of work available on electron-beam induced synthesis techniques with in situ capabilities. Particular emphasis is placed on the electron beam-induced synthesis of nanostructures conducted inside a TEM, viz. the e-beam is the sole (or primary) agent triggering and driving the synthesis process.
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Beitrag zur Entwicklung des Elektronenstrahl-Mehrspot/Mehrprozess-Schweißens von Gusseisen/Gusseisen- und Gusseisen/Stahl-Verbindungen ohne SchweißzusatzstoffeRüthrich, Karsten 17 April 2014 (has links)
Ziel der Arbeit war die Entwicklung des Elektronenstrahl-Mehrspot/Mehrprozess-Schweißens für Gusseisen/Gusseisen- und Gusseisen/Stahl-Verbindungen ohne Schweißzusatzstoffe. Im Vergleich zum Einbad-Schweißen entsteht beim Mehrbad-Schweißen eine porenarme Schweißnaht, gleichzeitig senkt sich die Schweißnahthärte geringfügig ab. Dabei kann die Kaltrissbildung in der Schweißnaht für arteigene Gusseisen-Verbindungen nicht unterdrückt werden. Für Mischverbindungen ist der Strahlversatz der bestimmende Schweißparameter beim Mehrbad-Schweißen. Über diesen kann sowohl die chemische Zusammensetzung der Schweißnaht eingestellt als auch ohne Vorwärmen eine kaltrissfreie Schweißnaht für Gusseisen/Stahl-Verbindungen erzeugt werden. Für die prozessintegrierte Wärmebehandlung der Fügezone wurde ein neues EB-Thermofeld entwickelt. Durch den Thermofeldeinsatz konnte die Aufhärtung in der Schmelz- und Wärmeeinflusszone signifikant reduziert werden und die mechanischen Eigenschaften der Schweißverbindungen wurden deutlich verbessert.
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