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New methods for increasing cutting tools effort
Janák, Marcel ; Humár, Anton (oponent) ; Zemčík, Oskar (vedoucí práce)
This bachelor thesis deals about methods which increases the effort of cutting tools. The first part includes the base scheme of cutting tools separation and tool materials. The second part is centreds on common effects which influences increasing of cutting tools effort and actual methods which are used in practises. In the third part are comparisons of methods which increases the cutting tools effort between ISCAR and their rivals.
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Semiconductor diagnostics and monitoring of chemical reactions by SIMS method
Janák, Marcel ; Skladaný, Roman (oponent) ; Bábor, Petr (vedoucí práce)
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a powerful surface science technique with high sensitivity for elemental composition. This work demonstrates TOF-SIMS abilities in three different research areas. The first part deals with the localization of high voltage dies defects, which is necessary for their further characterization by the TOF-SIMS method. For this purpose, an experimental setup with control software allowing automated measurement of leakage current tests at various die locations was proposed. The second part deals with the quantification of Mg dopant depth profiles in various AlGaN samples. The quantification is based on the RSF method and allows the characterization of doped AlGaN heterostructures for high electron mobility transistors (HEMT) or various optoelectronic devices. A set of 12 Mg doped AlGaN calibration samples for quantification of depth profiles was prepared by the ion implantation technique. The last part demonstrates the abilities of the static TOF-SIMS method in heterogeneous catalysis research. Our primary research objective is the dynamics of catalytic carbon monoxide oxidation to carbon dioxide on platinum polycrystalline microstructures at high vacuum pressures. In this work, we present the first real-time observations of spatiotemporal patterns of varying surface coverages during distinct catalyst regimes. TOF-SIMS observations were correlated with analogous scanning electron microscopy (SEM) observations of gas-phase- and temperature-induced processes on Pt surfaces.
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Calibration of SIMS method by implantation profiles
Janák, Marcel ; Průša, Stanislav (oponent) ; Bábor, Petr (vedoucí práce)
This bachelor thesis is concerned with a quantitative analysis of the dopant (C, H, Mg, O) distribution in MOCVD-grown AlGaN HEMTs by TOF.SIMS 5 instrument with cesium and oxygen sputtering. The main reason for the development of RSF SIMS measurement quantification method is a hardly predictable phenomenon of preferential sputtering and matrix effect. Calibration samples, prepared by ion implantation technique into homogeneous and periodic III-nitride AlN, GaN structures, are reproduced by an ion-atom interaction program TRIM. A part of this work is likewise a quantification of AlGaN matrix.
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Studium katalytické oxidace oxidu uhelnatého pomocí AFM/SEM
Hrůza, Dominik ; Janák, Marcel (oponent) ; Bábor, Petr (vedoucí práce)
Tato diplomová práce se zabývá studiem oxidace oxidu uhelnatého na platině pomocí korelativní mikroskopie AFM/SEM, která je v odborné literatuře pro tuto oblast výzkumu doposud opomíjena. V úvodu je provedena deskripce fungování použitých metod. Dále je teoreticky objasněna zkoumaná reakce, popsány oxidy na platině a současné směry vědeckého bádání. Na teoretickou část úzce navazuje experimentální část, kde je nejdříve popsán přenos experimentu mezi elektronovými mikroskopy a řešená úskalí spojená s tímto přenosem. Na to je navázáno provedení in-situ pozorování vlivu modifikací iontovým svazkem na zkoumanou reakci. Tato měření jsou porovnána pomocí elektronového a iontového svazku a je provedena deskripce jednotlivých povrchových dějů. Výsledky experimentů ukazují na nové možnosti ovlivnění chemických reakcí prostřednictvím modifikace povrchu a poskytují argumenty pro teorii podpovrchových forem oxidů. Následně jsou zkoumány možné vlivy hrotu na reakci a je objasněna možnost přímé modifikace povrchu pomocí rytí. Na závěr je provedena časová spektroskopie a mapování povrchu pro desorpční reakční vlnu, která přiblíží vliv průchodu chemické vlny pod hrotem. Součástí práce jsou také spektroskopické analýzy povrchu, které poskytují oporu pro závěry této práce.
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Semiconductor diagnostics and monitoring of chemical reactions by SIMS method
Janák, Marcel ; Skladaný, Roman (oponent) ; Bábor, Petr (vedoucí práce)
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a powerful surface science technique with high sensitivity for elemental composition. This work demonstrates TOF-SIMS abilities in three different research areas. The first part deals with the localization of high voltage dies defects, which is necessary for their further characterization by the TOF-SIMS method. For this purpose, an experimental setup with control software allowing automated measurement of leakage current tests at various die locations was proposed. The second part deals with the quantification of Mg dopant depth profiles in various AlGaN samples. The quantification is based on the RSF method and allows the characterization of doped AlGaN heterostructures for high electron mobility transistors (HEMT) or various optoelectronic devices. A set of 12 Mg doped AlGaN calibration samples for quantification of depth profiles was prepared by the ion implantation technique. The last part demonstrates the abilities of the static TOF-SIMS method in heterogeneous catalysis research. Our primary research objective is the dynamics of catalytic carbon monoxide oxidation to carbon dioxide on platinum polycrystalline microstructures at high vacuum pressures. In this work, we present the first real-time observations of spatiotemporal patterns of varying surface coverages during distinct catalyst regimes. TOF-SIMS observations were correlated with analogous scanning electron microscopy (SEM) observations of gas-phase- and temperature-induced processes on Pt surfaces.
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Calibration of SIMS method by implantation profiles
Janák, Marcel ; Průša, Stanislav (oponent) ; Bábor, Petr (vedoucí práce)
This bachelor thesis is concerned with a quantitative analysis of the dopant (C, H, Mg, O) distribution in MOCVD-grown AlGaN HEMTs by TOF.SIMS 5 instrument with cesium and oxygen sputtering. The main reason for the development of RSF SIMS measurement quantification method is a hardly predictable phenomenon of preferential sputtering and matrix effect. Calibration samples, prepared by ion implantation technique into homogeneous and periodic III-nitride AlN, GaN structures, are reproduced by an ion-atom interaction program TRIM. A part of this work is likewise a quantification of AlGaN matrix.
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New methods for increasing cutting tools effort
Janák, Marcel ; Humár, Anton (oponent) ; Zemčík, Oskar (vedoucí práce)
This bachelor thesis deals about methods which increases the effort of cutting tools. The first part includes the base scheme of cutting tools separation and tool materials. The second part is centreds on common effects which influences increasing of cutting tools effort and actual methods which are used in practises. In the third part are comparisons of methods which increases the cutting tools effort between ISCAR and their rivals.
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