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Study of magnetic nanostructures for spintronics
Kameš, Jaroslav ; Nebojsa, Alois (referee) ; Urbánek, Michal (advisor)
The Cu/NiFe/Cu/Co/(CoOx) spin-valves have been prepared by the ion-beam sputtering method. Their GMR ratio and the time stability have been investigated by the magnetoresistance and the MOKE measurements at room temperature. The reproducibility of the preparation of the samples have been studied as well, i.e. two identically configurations of the layers should have the same magnetotransport properties.
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Utilization of artificially created weak magnetic field for navigation in 3D space
Váňa, Dominik ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
This master's thesis focuses on the utilization of an artificially created weak magnetic field for navigation in 3D space. The theoretical part of this work deals with the general properties of the magnetic field and with its description. The next section of the theoretical part contains an overview of measuring principles for magnetic field measurements. Based on various types of measuring principles, the thesis elaborates on commercially available miniature sensors for magnetic field measurement with a measuring range up to 10 mT. The work focuses mainly on the magnetoresistive principle and fluxgate sensors. Furthermore, the theoretical part contains descriptions of methods for modeling the magnetic field of simple permanent magnets and various magnet assemblies. Lastly, the theoretical part involves a patent search of devices used for locating magnets that are installed in an intramedullary nail, which is used in intramedullary stabilization used on fractures of human bones. By locating the magnet in the nail, it is possible to precisely determine the position of the mounting holes. The practical part of the thesis deals with the analysis of magnetic field behavior in the vicinity of various magnetic assemblies, which were modeled in COMSOL Multiphysics using the finite element method. The models were created with the aim of analysing the behaviour of the magnetic field in the vicinity of the magnets and at the same time to find possible analytical functions that could be used to determine the position of the magnet in space relative to the probe. The result of this work is an analysis of various assemblies, which contains graphs of different dependencies and prescription of polynomial functions that approximate these dependencies. Another part of the thesis is the design of a probe that serves to locate the magnetic target. The work describes two possible methods of localization. For the differential method, a user interface in LabVIEW was created. The probe based on this method is fully capable of locating the magnet in the 2D plane. The state space search method is described only in theory.
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Cell labeling with magnetic particles
Kukhta, Dziyana ; Janoušek, Oto (referee) ; Čmiel, Vratislav (advisor)
This bachelor thesis describes the movement of cells labelled with magnetic nanoparticles in the magnetic field in the direction of the magnet. First, it describes two types of magnets: permanent magnet and electromagnet. Then, it is dedicated to magnetic field sensors, magnetic nanoparticles and their incorporation in cells, optical systems for detecting cell movement and the effect of electromagnetic fields on cells. The practical part is dedicated to the incorporation of nanoparticles in cells, the measurement of the magnetic field intensity of a neodymium magnet and an electromagnet, and the methods of electromagnet control. It also describes the effect of electromagnetic fields on fibroblasts and the concentration of nanoparticles on the ability of the labelled cells to react to a magnetic field. The last part is dedicated to the production of a flow chamber, the analysis of the movement of cells in the chamber and the subsequent capture of cells in various magnetic fields.
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Magnetic multilayers for spintronics applications
Vaňatka, Marek ; Dvořák, Petr (referee) ; Urbánek, Michal (advisor)
Magnetic multilayers have applications as magnetic field sensors or magnetic memory cells. Mastering the methods of fabrication and characterization of the structures such as spin valve or magnetic tunnel junction is an important step towards more complicated spintronics devices. This work summarizes basic theory of magnetism, magnetotransport properties, and it describes basic applications of magnetic multilayers. The experimental part of this work deals with the sample preparation by ion beam sputtering (IBS), ion beam assisted deposition (IBAD), and characterization of prepared multilayers by measuring anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), or tunnel magnetoresistance (TMR).
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Utilization of artificially created weak magnetic field for navigation in 3D space
Váňa, Dominik ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
This master's thesis focuses on the utilization of an artificially created weak magnetic field for navigation in 3D space. The theoretical part of this work deals with the general properties of the magnetic field and with its description. The next section of the theoretical part contains an overview of measuring principles for magnetic field measurements. Based on various types of measuring principles, the thesis elaborates on commercially available miniature sensors for magnetic field measurement with a measuring range up to 10 mT. The work focuses mainly on the magnetoresistive principle and fluxgate sensors. Furthermore, the theoretical part contains descriptions of methods for modeling the magnetic field of simple permanent magnets and various magnet assemblies. Lastly, the theoretical part involves a patent search of devices used for locating magnets that are installed in an intramedullary nail, which is used in intramedullary stabilization used on fractures of human bones. By locating the magnet in the nail, it is possible to precisely determine the position of the mounting holes. The practical part of the thesis deals with the analysis of magnetic field behavior in the vicinity of various magnetic assemblies, which were modeled in COMSOL Multiphysics using the finite element method. The models were created with the aim of analysing the behaviour of the magnetic field in the vicinity of the magnets and at the same time to find possible analytical functions that could be used to determine the position of the magnet in space relative to the probe. The result of this work is an analysis of various assemblies, which contains graphs of different dependencies and prescription of polynomial functions that approximate these dependencies. Another part of the thesis is the design of a probe that serves to locate the magnetic target. The work describes two possible methods of localization. For the differential method, a user interface in LabVIEW was created. The probe based on this method is fully capable of locating the magnet in the 2D plane. The state space search method is described only in theory.
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Geneticky modifikované organizmy v potravinách
Košíková, Romana
My bachelor thesis genetically modified organisms in food deals zoom GMOs in terms of crops , animals and microorganisms and their use in the world. The aim was to bring positive and also negative prospects associated with the use of GMOs . The paper referred to the legislation in force and labeling GMO foods.
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Cell labeling with magnetic particles
Kukhta, Dziyana ; Janoušek, Oto (referee) ; Čmiel, Vratislav (advisor)
This bachelor thesis describes the movement of cells labelled with magnetic nanoparticles in the magnetic field in the direction of the magnet. First, it describes two types of magnets: permanent magnet and electromagnet. Then, it is dedicated to magnetic field sensors, magnetic nanoparticles and their incorporation in cells, optical systems for detecting cell movement and the effect of electromagnetic fields on cells. The practical part is dedicated to the incorporation of nanoparticles in cells, the measurement of the magnetic field intensity of a neodymium magnet and an electromagnet, and the methods of electromagnet control. It also describes the effect of electromagnetic fields on fibroblasts and the concentration of nanoparticles on the ability of the labelled cells to react to a magnetic field. The last part is dedicated to the production of a flow chamber, the analysis of the movement of cells in the chamber and the subsequent capture of cells in various magnetic fields.
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Study of magnetic nanostructures for spintronics
Kameš, Jaroslav ; Nebojsa, Alois (referee) ; Urbánek, Michal (advisor)
The Cu/NiFe/Cu/Co/(CoOx) spin-valves have been prepared by the ion-beam sputtering method. Their GMR ratio and the time stability have been investigated by the magnetoresistance and the MOKE measurements at room temperature. The reproducibility of the preparation of the samples have been studied as well, i.e. two identically configurations of the layers should have the same magnetotransport properties.
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