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Testing of sliding coatings for space applications
Velička, Jan ; Pouzar, Josef (referee) ; Košťál, David (advisor)
This bachelor thesis deals with sliding coatings for use in space applications. In the experimental part, the number of cycles to wear for a molybdenum disulfide based coating was investigated. This coating was deposited on a beryllium copper CuBe substrate. The coating was tested for its possible application to bolt threads. The coefficient of friction of all samples was measured on a tribometer in an atmospheric environment. The specimens were loaded with a normal force of 35 N during the measurement. The number of cycles to wear was compared for specimens differing in coating time. The number of cycles was found to be similar for lower coating times. Then the number of cycles to wear started to increase with the coating time. From the findings, it can be said that increasing the coating time increases the coating life. Such a coating is suitable for the protection of bolts against galling.
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Photoluminiscence study of thin layers of MoS2
Kuba, Jakub ; Kunc,, Jan (referee) ; Bartoš, Miroslav (advisor)
The thesis deals with study of thin layers of transition metal dichalcogenides, especially of molybdenum disulfide. Nanostructures were fabricated on two-dimensional crystals of MoS2 and WSe2. Within followed analysis attention was paid to the photoluminescence properties. In the thesis transition metal dichalcogenides are reviewed and description of the modified process of preparation by micromechanical exfoliation is given.
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Preparation of 2D heterostructures
Ředina, Dalibor ; Hrabovský, Miloš (referee) ; Bartoš, Miroslav (advisor)
This bachelor's thesis refers about preparation of 2D hetestructures here at the IPE, BUT. The first theoretical part deals with properties of graphene, molybdenum disulfide and 2D heterostructures in general. Comprehensive overview is provided by basic facts about properties and allotropic modifications of carbon. Next part of this thesis outlines methods used in the fabrication of heterostructures and highlights presumably the best one. Experimental part deals with optimization of this method. Successive steps of this method are improved by various adjustments in order to achieve the highest success rate in the fabrication of these heterostructures. Result of this approach is stated in this thesis.
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Technological challenges in the fabrication of MoS.sub.2./sub./diamond heterostructures
Varga, Marián ; Sojková, M. ; Hrdá, J. ; Hutar, P. ; Parsa Saeb, S. ; Vanko, G. ; Pribusova Slusna, L. ; Ondič, Lukáš ; Fait, Jan ; Kromka, Alexander ; Hulman, M.
Nowadays, 2D materials are one of the most studied classes of materials. In addition to the most famous graphene, progress has been achieved in studying and using fundamental properties of transition metal dichalcogenides (TMD). Complementary, diamond as a representative of 3D materials has gained a reputation as an extremely versatile material due to its extraordinary combination of physical/chemical/electrical/optical properties. Besides these particular forms of 2D and 3D materials, their heterostructures have become very attractive due to new phenomena and functions (bandgap engineering, enhanced charge transport, optical interaction, etc.). However, individual technological procedures are still minimally investigated and described. Here, we will demonstrate a proof-of-concept for the preparation of MoS2/diamond heterostructures, where two different strategies were employed: a) growth of MoS2 layers on diamond films, and b) growth of diamond films on Si/MoS2 substrates.
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Ab initio study of electronic structure of 2D materials
Pekár, Zdenko ; Nezval, David (referee) ; Černý, Miroslav (advisor)
This bachelor’s thesis begins with an overview of basic terminology and principles regarding transition metal dichalcogenides and density functional theory. The theoretical part then brings several examples of atomic configuration of such materials and aproximations for the exchange-correlation functional. The practical part focuses on computational simulation and optimization of cells for various phases of transition metal dichalcogenides and their combinations, and compares their properties to those found in scientific literature and also gathers new, so far untested information about these materials.
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Photoluminiscence study of thin layers of MoS2
Kuba, Jakub ; Kunc,, Jan (referee) ; Bartoš, Miroslav (advisor)
The thesis deals with study of thin layers of transition metal dichalcogenides, especially of molybdenum disulfide. Nanostructures were fabricated on two-dimensional crystals of MoS2 and WSe2. Within followed analysis attention was paid to the photoluminescence properties. In the thesis transition metal dichalcogenides are reviewed and description of the modified process of preparation by micromechanical exfoliation is given.
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Preparation of 2D heterostructures
Ředina, Dalibor ; Hrabovský, Miloš (referee) ; Bartoš, Miroslav (advisor)
This bachelor's thesis refers about preparation of 2D hetestructures here at the IPE, BUT. The first theoretical part deals with properties of graphene, molybdenum disulfide and 2D heterostructures in general. Comprehensive overview is provided by basic facts about properties and allotropic modifications of carbon. Next part of this thesis outlines methods used in the fabrication of heterostructures and highlights presumably the best one. Experimental part deals with optimization of this method. Successive steps of this method are improved by various adjustments in order to achieve the highest success rate in the fabrication of these heterostructures. Result of this approach is stated in this thesis.
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