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Effect of the substrate crystalline orientation on the surface morphology and boron incorporation into epitaxial diamond layers
Voves, J. ; Pošta, A. ; Davydova, Marina ; Laposa, A. ; Povolný, V. ; Hazdra, P. ; Lambert, Nicolas ; Sedláková, Silvia ; Mortet, Vincent
Epitaxial growth of diamond is critically important for the fabrication of diamond-based electronic devices. The emerging study of the epitaxial diamond growth on the (113) vicinal surfaces evidences highly needed high growth rates and low structural defects concentrations with both p- and n-type doping. In this work, we compare the morphology and dopant concentration incorporation of heavily boron-doped (113) epitaxial diamond layers with conventionally studied (100) and (111) epitaxial layers. Epitaxial layers were grown using resonance cavity Microwave Plasma Enhanced Chemical Vapor Deposition (MWPECVD) system. The surface morphology of epitaxial layers was studied by optical microscopy and atomic force microscopy, whereas the boron incorporation homogeneity was determined by Raman spectroscopy mapping.
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Study of the structural properties of model ceria based catalysts
Beran, Jan
This work is concerning the study of model ceria based calalysts structure by methods of electron diffraction RHEED and photoelectron spectroscopy XPS. The influence of deposition conditions and substrate on the growth of epitaxial cerium oxide films on copper single crystals is described in detail. The work then describes the interaction of cerium and tin in model systems and the creation of SnCeOx mixed oxide and its structure. In the last chapter, the interaction of palladium with cerium and tin oxide layers is examined, and the creation of paladium bimetallic alloys is described. Powered by TCPDF (www.tcpdf.org)
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Study of the structural properties of model ceria based catalysts
Beran, Jan
This work is concerning the study of model ceria based calalysts structure by methods of electron diffraction RHEED and photoelectron spectroscopy XPS. The influence of deposition conditions and substrate on the growth of epitaxial cerium oxide films on copper single crystals is described in detail. The work then describes the interaction of cerium and tin in model systems and the creation of SnCeOx mixed oxide and its structure. In the last chapter, the interaction of palladium with cerium and tin oxide layers is examined, and the creation of paladium bimetallic alloys is described. Powered by TCPDF (www.tcpdf.org)
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Study of the structural properties of model ceria based catalysts
Beran, Jan ; Mašek, Karel (advisor) ; Olejník, Kamil (referee) ; Lykhach, Yaroslava (referee)
This work is concerning the study of model ceria based calalysts structure by methods of electron diffraction RHEED and photoelectron spectroscopy XPS. The influence of deposition conditions and substrate on the growth of epitaxial cerium oxide films on copper single crystals is described in detail. The work then describes the interaction of cerium and tin in model systems and the creation of SnCeOx mixed oxide and its structure. In the last chapter, the interaction of palladium with cerium and tin oxide layers is examined, and the creation of paladium bimetallic alloys is described. Powered by TCPDF (www.tcpdf.org)
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Preparation and characterization of epitaxial tungsten oxide thin films
Pavlíková, Romana ; Mašek, Karel (advisor) ; Olejník, Kamil (referee)
Tungsten oxide thin films were prepared by vacuum evaporation on surfaces of Pd(111), Cu(111), Cu(110) and Cu(100) single crystals and studied by RHEED, XPS and AFM methods. The tungsten oxide deposition was done at temperatures from 300 řC to 400 řC in UHV or in oxygen atmosphere. The best deposition conditions - substrate temperature of 400 řC and oxygen atmosphere - were found resulting in growth of epitaxial and only partially reduced thin films. Thin films grown on the Pd(111) and Cu(111) surfaces consisted of two phases: a nearly atomically flat phase with (100) epitaxial plane and a phase formed by three dimensional particles with (111) epitaxial plane. Thin film deposited on Cu(100) also consisted of two phases: a flat film with (100) epitaxial plane and self-organised 1D structures parallel to Cu[010] and Cu[001] directions. Thin film prepared on the Cu(110) surface contained solely 1D structures parallel to Cu[1-10] surface direction. Capability of the partially reduced thin films for oxidation was studied. We applied oxidation using RF oxygen plasma, O2 exposure at elevated temperature and exposure to atmosphere. Thermal stability of the WO3/Cu(110) system was also investigated by heating up to 620 řC.
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Study of influence of the substrate temperature on the structure of epitaxial tungsten oxide layers
Pavlíková, Romana ; Mašek, Karel (advisor) ; Veltruská, Kateřina (referee)
Purpose of this thesis is a study of substrate temperature influence on structure, chemical composition and morphology of tungsten oxide thin films prepared by oxidation of a tungsten single crystal W(110) using a radio frequency plasma source. Thin film's parameters were observed by RHEED, XPS, AFM snad SEM. The substrate was oxidized at room temperature (RT) and at temperatures of 400ř C, 500ř C and 550ř C. In the first and the second case, produced thin films were amorphous and epitaxial structure was obtained by recrystallization. At the temperature of 500ř C, an epitaxial thin film was produced directly. After further heating at the temperature of 550ř C we got polycrystalline thin film without orientation of the crystal grains. All the epitaxial thin films had (111) crystallographic plane parallel to substrate surface. The tungsten oxide layers grew with relatively hight surface roughness in the order of several nanometers.
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Epitaxial rectrystalization of the Ni/MgO(001)interface
Vacík, Jiří ; Naramoto, H. ; Yamamoto, S. ; Narumi, K. ; Havránek, Vladimír
Process of recrystallization of the epitaxially grown Ni layer deposited on the MgO(001) single crystal is studied. Thin Ni layer prepared by the vapor deposition of Ni on the MgO substrate kept were annealed between 500 and 1000 0C and systematically analyzed by Rutherford backscattering, X-ray diffraction and atomic force microscopy. Dramatic change in evolution of the crystalline quality was observed during the thermal treatment. The strain and defect density gradually decreased and at the temperature 1000 0C the strain-free Ni/MgO(001) interface was obtained.
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