National Repository of Grey Literature 104 records found  beginprevious91 - 100next  jump to record: Search took 0.01 seconds. 
Study of AFM pull-off force on graphite/graphene layers in the perspective of nanosensoric applications
Pagáčová, Lenka ; Nebojsa, Alois (referee) ; Bartošík, Miroslav (advisor)
The diploma thesis deals with force-distance spectroscopy method as a tool for determining pull-off force on graphit/graphene sheets under varied conditions. There is described also a contact angle method which is used to idetify contact angles of water on six investigated samples. Results of both method were discussed with respect to utilization of force-distance spectroscopy in wetting measurements of materials. Finally it was carried out modification of graphen sheet by local anodic oxidation.
Aplication of SPM in study and modification of ultrathin films Pt, Co and graphene
Lišková, Zuzana ; Červenka,, Jiří (referee) ; Bartošík, Miroslav (advisor)
This diploma thesis deals with the preparation of the very thin films and their investigation by scanning probe microscopy methods. The ultrathin films of Pt on Pt(111) were created by pulsed laser deposition and the ultrathin films of Co on Pt(111) were deposited by thermal evaporation. The coverage of the substrate was much smaller than one monolayer (in order of hundredths of monolayer). The nucleation theory was verified by these experiments using so-called Onset method. Further graphene sheets were prepared on layer of Si/SiO2 by the mechanical exfoliation from the graphite crystal. The fabricated graphene sheets were studied by micro-Raman spectroscopy, microreflectometry, atomic force microscopy and similar techniques. These methods proved the thinnest graphite layers were consisted of two graphene monolayers.
Analysis of the transport properties of graphene nanostructures
Novák, Martin ; Bartošík, Miroslav (referee) ; Lišková, Zuzana (advisor)
Graphene transport properties are analysed in this thesis. They are strongly dependent on doping with charge carriers. The number of charge carriers can be influenced by electric field, substrate or surface adsorbates. The graphene field-effect transistor (FET) has been prepared. Graphene made by chemical vapor deposition (CVD) has been con tacted through gold structures made by electron beam lithography (EBL). Dependences on electrode configuration, gate voltage and used substrate are observed.
Photocontrolled Biomolecules
Planer, Jakub ; Bartošík, Miroslav (referee) ; Vácha,, Robert (referee) ; Kulhánek, Petr (advisor)
This work is focused on molecular dynamics simulations of artificial photosensitive ion channel and AFM probe. To assemble this ion channel, DFT methods were employed for reparametrization of the GAFF force field describing the bridged azobenzene, which was used as a light controlled molecular switch. We proved by molecular dynamics simulations that newly developed parameters correctly describe behavior of assembled model of ion channel in a lipid bilayer. We also constructed a model of AFM probe and observed formation of water meniscus between the AFM probe and surface, both made of -quartz, by employing molecular dynamics simulations. A contribution of this work is the set of new parameters extending GAFF force field for description of the bridged azobenzene. We also verified functionality of ion channel model and model of AFM probe, which can be used for the further water meniscus studies.
The graphene structures suitable for field effect transistors
Kurfürstová, Markéta ; Bartošík, Miroslav (referee) ; Mach, Jindřich (advisor)
This bachelor’s thesis is focused on preparation of graphene structures suitable for field effect transistors. In the first section, graphene is characterized in terms of its properties and prepataion methods. The second part sums up semiconductor technology, focusing on transistors with graphene layer. Next, electron beam litography method is presented, which had been used for preparation of the structures. Finally, an experimental procedure of graphene structures manufacture is described.
Design, Fabrication and Testing of Environmental Chamber for Atomic Force Microscope and for Electronic Measurements of Nanosensors
Cahlík, Aleš ; Mach, Jindřich (referee) ; Bartošík, Miroslav (advisor)
This thesis deals with the concept of the chamber for atomic force microscope device NTegra Prima or alternatively for stand-alone measurements of nanosensors. The chamber will be used for defined modification of ambient conditions in space around measured sample. In first part, the theoretical principles of influence of ambient conditions on AFM methods are discussed. In the second chapter, the principles of graphene sensors measurements are showed. Further the reasons and requirements for designing this chamber are introduced. Main part deals with description of design. At the end the results of stress analysis and wall deflection of evacuated chamber are presented.
Design and Testing of Algorithms for Controlling the Relative Humidity in the AFM Chamber
Nezval, David ; Šulc, Dalibor (referee) ; Bartošík, Miroslav (advisor)
This bachelor's thesis deals with controlling the relative humidity in the AFM chamber. There are used controllers based on principles of PID controlling with constant coefficient, self-tuning PID controlling and fuzzy controlling for the automatic controlling. This principles are explained and with this knowledge are designed and tested four algorithm for controlling the relative humidity.
Study of Water Meniscus Formation between the AFM Tip and NaCl Surface
Švarc, Vojtěch ; Spousta, Jiří (referee) ; Bartošík, Miroslav (advisor)
This bachelor's thesis deals with the study of water meniscus formation between the AFM tip and NaCl surface. This is an indirect method for the study of meniscus by observation of holes and hillocks created on the NaCl surface, in dependence on the relative humidity, cleaning the tip, time of keeping the on the surface apllied voltage tip-surface.
Application of Graphene Modified by FIB in Sensors of Relative Humidity
Kormoš, Lukáš ; Lišková, Zuzana (referee) ; Bartošík, Miroslav (advisor)
This thesis is focused on potential use of graphene in relative humidity sensing. The effect of water vapor on electrical properties of graphene is described as a change in graphene layer resistivity. The impact of surface distortion created by focused ion beam is also studied. The experiment dealing with the influence of graphene sensor area on its water molecules sensing capability is described in the last part.
Preparation of graphene layers by various methods and characterization of their properties
Zahradníček, Radim ; Bartošík, Miroslav (referee) ; Lišková, Zuzana (advisor)
This bachelor's thesis deals with the production of graphene by different methods. Graphene was prepared by mechanical exfoliation and chemical methods. Graphene oxide (GO) was first prepared by modified Hummers method and disolved the solution in isopropyl alcohol. It was subsequently reduced by photoreduction, UV radiation and thermal reduction. Produced graphene samples were characterized using optical microscopy, electron microscopy, atomic force microscopy, Raman spectroscopy and X$-$ray photoelectron spectroscopy. Measurement results and evaluation of production quality of graphene are shown in this work.

National Repository of Grey Literature : 104 records found   beginprevious91 - 100next  jump to record:
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