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Preparation of ultra sharp tips for STM TERS applications
Šilhan, Lukáš ; Man, Ondřej (referee) ; Jan, Vít (advisor)
The goal of this bachelor thesis is preparation of Au tips by electrochemical etching. The theoretical part deals with comparison of microscopy techniques for materials surface characterization and Raman spectroscopy. The experimental part is focused on the settings of optimal etching parametres to gain appropriate geometry of fabricated tips. Function of tips is verified by evaluation of data gained by experimental measuring with this tips. Prepared tips are suitable for applications such as STM and TERS.
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The importance of the deformation necks in forming
Kučera, Radek ; Podaný, Kamil (referee) ; Peterková, Eva (advisor)
The aim of this bachelor thesis is elaboration of the research themed deformation necks in forming technology. Particular methods of spreading of the deformation necks are described in this thesis. The advantages and disadvantages are reviewed also as its use in practice. Moreover comparison of the most used methods of spreading of deformation necks had been carried out. Further the connection of deformation necks and forming limit diagram had been stated. The thesis also presents summary of the automated methods of deformation necks analysis.
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Characterisation for the cold field-emission sources intended for electron microscopy
Vašíček, Martin ; Tománek, Pavel (referee) ; Grmela, Lubomír (advisor)
This work deals with the theoretical foundations of electron emission into vacuum, various types of emissions, focused on the cold-emission and Schottky emission and the principle of quantum tunneling. The next part deals with the technical implementation of electron sources with a detailed study of the methodology of laboratory production of cathodes by electrochemical etching and construction of electron microscopes, using field-emission sources. This work also contains methods for measuring, processing and evaluation of electrical characteristics of emission sources.
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Fabrication of the STM tips - static and dynamic etching method
Jonner, Jakub ; Spousta, Jiří (referee) ; Kostelník, Petr (advisor)
This bachelor thesis deals with the static and dynamic method of electrochemical etching way of fabrication tips for Scanning Tunneling Microscope (STM). This thesis describes basic principles of the mentioned methods and the construction solutions of the etching apparatuses. An extensive set of measurements was performed in order to obtain the main goal of the thesis – to determine the influence of various etching parameters on the process and final product. In case of static method, we used various concentrations of KOH solution, depths of plunge of the wolfram wire in to the etching solution and setpoints of the etching voltage. In case of dynamic method, we used also various concentrations of KOH solution and different settings of the etching solution flow rate and setpoints of the etching voltage. The ideal configuration of the etching parameters is presented at the end of the thesis as well with the comparison of the etching results from both of the eching methods.
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Electrochemical etching of silicon
Vrzal, Pavel ; Voborný, Stanislav (referee) ; Šamořil, Tomáš (advisor)
The electrochemical etching is very used technique for semiconductor materials modification. Different structures which find applications in many fields (biotechnology, nanotechnology or electronics) can be prepared by this technique. The task of bachelor’s thesis was preparation of porous silicon using electrochemical etching. At first, a study dedicated to porous Si was carried out. Experimental part of this work deals with a design of etching cell which was used for preparation of porous silicon by electrochemical etching. In addition, the porous Si was prepared by metal assisted chemical etching. Subsequently, created structures were analyzed by scanning electron microscopy. Photoluminescence properties of porous silicon were studied as well.
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Electrochemical etching of silicon
Vrzal, Pavel ; Voborný, Stanislav (referee) ; Šamořil, Tomáš (advisor)
The electrochemical etching is very used technique for semiconductor materials modification. Different structures which find applications in many fields (biotechnology, nanotechnology or electronics) can be prepared by this technique. The task of bachelor’s thesis was preparation of porous silicon using electrochemical etching. At first, a study dedicated to porous Si was carried out. Experimental part of this work deals with a design of etching cell which was used for preparation of porous silicon by electrochemical etching. In addition, the porous Si was prepared by metal assisted chemical etching. Subsequently, created structures were analyzed by scanning electron microscopy. Photoluminescence properties of porous silicon were studied as well.
|
|
|
Preparation of ultra sharp tips for STM TERS applications
Šilhan, Lukáš ; Man, Ondřej (referee) ; Jan, Vít (advisor)
The goal of this bachelor thesis is preparation of Au tips by electrochemical etching. The theoretical part deals with comparison of microscopy techniques for materials surface characterization and Raman spectroscopy. The experimental part is focused on the settings of optimal etching parametres to gain appropriate geometry of fabricated tips. Function of tips is verified by evaluation of data gained by experimental measuring with this tips. Prepared tips are suitable for applications such as STM and TERS.
|
|
|
Electrochemical etching of silicon
Vrzal, Pavel ; Voborný, Stanislav (referee) ; Šamořil, Tomáš (advisor)
The electrochemical etching is very used technique for semiconductor materials modification. Different structures which find applications in many fields (biotechnology, nanotechnology or electronics) can be prepared by this technique. The task of bachelor’s thesis was preparation of porous silicon using electrochemical etching. At first, a study dedicated to porous Si was carried out. Experimental part of this work deals with a design of etching cell which was used for preparation of porous silicon by electrochemical etching. In addition, the porous Si was prepared by metal assisted chemical etching. Subsequently, created structures were analyzed by scanning electron microscopy. Photoluminescence properties of porous silicon were studied as well.
|
|
|
Characterisation for the cold field-emission sources intended for electron microscopy
Vašíček, Martin ; Tománek, Pavel (referee) ; Grmela, Lubomír (advisor)
This work deals with the theoretical foundations of electron emission into vacuum, various types of emissions, focused on the cold-emission and Schottky emission and the principle of quantum tunneling. The next part deals with the technical implementation of electron sources with a detailed study of the methodology of laboratory production of cathodes by electrochemical etching and construction of electron microscopes, using field-emission sources. This work also contains methods for measuring, processing and evaluation of electrical characteristics of emission sources.
|
|
|
The importance of the deformation necks in forming
Kučera, Radek ; Podaný, Kamil (referee) ; Peterková, Eva (advisor)
The aim of this bachelor thesis is elaboration of the research themed deformation necks in forming technology. Particular methods of spreading of the deformation necks are described in this thesis. The advantages and disadvantages are reviewed also as its use in practice. Moreover comparison of the most used methods of spreading of deformation necks had been carried out. Further the connection of deformation necks and forming limit diagram had been stated. The thesis also presents summary of the automated methods of deformation necks analysis.
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