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Microscopic and spectroscopic analysis of elementary 2D materials
Jeřábek, František ; Procházka, Pavel (referee) ; Kolíbal, Miroslav (advisor)
Tato práce se zabývá analýzou struktur tvořených při depozici fosforu na monokrystal mědi Cu(111) za podmínek ultravysokého vakua. Součástí práce je komplexní shrnutí aktuálního pokroku v oblasti syntézy černého a modrého fosforenu. Kromě samotných metod přípravy je diskutována také předpovězená stabilita těchto struktur. V práci jsou prezentovány výsledky analýzy tří struktur pomocí skenovací tunelové mikroskopie a spektroskopie, prokazující možnost přípravy jednovrstvého modrého fosforenu na měděném substrátu. In-situ analýza stability připravených struktur pomocí skenovací tunelovací mikroskopie prokazuje velmi rychlou degradaci modrého fosforenu i za podmínek ultravysokého vakua.
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Preparation of elementary 2D materials and heterostructures
David, Jiří ; Redondo,, Jesús Rubén López-Roso (referee) ; Kolíbal, Miroslav (advisor)
This thesis is focused on the preparation of blue phosphorene on Ag(111) and Cu(111) substrates and on the preparation of heterostructure graphene/blue phosphorene on Cu(111) substrate. The structural properties of these materials were analyzed by LEED, LEEM, and STM. Chemical composition was measured by XPS. The first chapter describes the properties of blue phosphorene, the influence of the substrates on its growth, the current experimental state, and the advantages of heterostructures from 2D materials. The second chapter is focused on the optimization of blue phosphorene’s growth conditions. Next, a successful preparation of blue phosphorene on Cu(111) substrate is demonstrated. Additionally, a new growth mechanism of 2D materials is described. In the end, an attempt to prepare a heterostructure of blue phosphorene and graphene was made. The results show a possible feasibility of demonstrated approach.
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Microscopic and spectroscopic analysis of elementary 2D materials
Jeřábek, František ; Procházka, Pavel (referee) ; Kolíbal, Miroslav (advisor)
Tato práce se zabývá analýzou struktur tvořených při depozici fosforu na monokrystal mědi Cu(111) za podmínek ultravysokého vakua. Součástí práce je komplexní shrnutí aktuálního pokroku v oblasti syntézy černého a modrého fosforenu. Kromě samotných metod přípravy je diskutována také předpovězená stabilita těchto struktur. V práci jsou prezentovány výsledky analýzy tří struktur pomocí skenovací tunelové mikroskopie a spektroskopie, prokazující možnost přípravy jednovrstvého modrého fosforenu na měděném substrátu. In-situ analýza stability připravených struktur pomocí skenovací tunelovací mikroskopie prokazuje velmi rychlou degradaci modrého fosforenu i za podmínek ultravysokého vakua.
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Electronics and adsorption properties of model catalytic systems contains cerium
Cabala, Miloš ; Veltruská, Kateřina (advisor) ; Jiříček, Petr (referee) ; Polčík, Martin (referee)
Title: Electronics and adsorption properties of model catalytic systems contains cerium Author: Miloš Cabala Department: Department of Surface and Plasma Science, Supervisor: RNDr. Kateřina Veltruská, Department of Surface and Plasma Science, Abstract: The doctoral thesis contains the study of model catalyst systems based on cerium and ceria. The thesis deals with model systems of CeAg, CeO2/Cu(111), Ni- CeO2/Cu(111) a Ni-Sn-CeO2/Cu(111). We have studied these systems using photoelectron spectroscopy, ion scattering spectroscopy and low energy electron diffraction. Model systems were prepared under strictly defined conditions. The strong bimetallic interaction was observed on the CeAg layers. Molecular adsorption of carbon monoxide on CeAg was demonstrated. We also observed intensive reaction of these layers with oxygen. By measurements in different directions of surface Brillouin zone, we managed to reconstruct the band structure of the prepared CeO2/Cu(111) layer. We have shown that the Cu substrate interacts weakly with deposited CeO2 layer. This interaction results in a charge transfer from Cu into CeO2. Overall, in the valence spectrum we have identified three main electron bands corresponding to O 2p state bound in CeO2. It has been proven that the deposition of Ni on CeO2 layers leads to partial...
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Physically chemical properties of epitaxial films CeOx/Cu(111)
Duchoň, Tomáš ; Veltruská, Kateřina (advisor) ; Polčík, Martin (referee)
In this work a reversible transition between CeO2/Cu(111) and Ce2O3/Cu(111) was studied by metalic ceria evaporation and oxygen exposition. Prepared layers were characterised by XPS, ISS (and its angle resolved modification), LEED and XPD combined with computer modelling using EDAC code. Four reconstructi- on were identified within the transition - ( √ 7 × √ 7)R19.1◦ , ( √ 3 × √ 3)R30◦ , 3 × 3 and 4 × 4 - for which structural models were suggested. Prepared layers of Ce2O3/Cu(111) exhibiting the 4×4 reconstruction were identified as a cubic pha- se of Ce2O3 by the combination of all methods. The photoelectron spectroscopy study of the chemical state of layers revealed that reduction proceedes from the surface and oxidation is realised by oxygen diffusion into the volume.
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