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Magnetic transformation of metastable fcc Fe/Cu(100) films by focused ion beam
Gloss, Jonáš ; Cháb, Vladimír (referee) ; Urbánek, Michal (advisor)
Metastable paramagnetic face-centered cubic (fcc) Fe thin films deposited on a Cu(100) single-crystal are good candidates for focused ion-beam magnetic patterning, due to their structural and magnetic phase transformation to ferromagnetic body-centered cubic (bcc) Fe upon ion-beam irradiation. However, pure fcc Fe films undergo spontaneous transformation when their thickness exceeds 10 ML. This limit can be extended to approximately 22 ML by deposition of Fe at increased CO background pressures. We show that much thicker films can be grown by alloying with Ni, that stabilizes the fcc phase. The amount of Ni necessary to stabilize non-magnetic, metastable fcc Fe films in dependence on the residual background pressure during the deposition is determined and a phase diagram revealing the metastable region is presented. It is also shown that the stabilizing effect of CO can be removed by artificial O saturation of the surface and thus the Ni-stabilized films can be grown also in systems with lower vacuum. Finally, we present fabrication of micro- and nanostructures in 44 ML thick films of Fe alloyed with Ni on Cu(100) by focused ion beam.
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Study of Properties of Surface Plasmon Polaritons on Magnetic Materials
Dvořák, Petr ; Schmidt, Eduard (referee) ; Kalousek, Radek (advisor)
The diploma thesis deals with the experimental study of surface plasmon polaritons (SPPs) on nano-structures with the Au/Co/Au multilayer. Plasmonic structures were prepared by the electron beam lithography and by the focused ion beam. A Scanning optical near-field microscope was used for detection of surface plasmon polaritons. SPPs were confirmed by the experiment with different polarizations of the illuminating light. Furthermore, differences in plasmon interference wavelengths was measured for different surface dielectric functions. Finally, the decantation of the SPPs interference image was measured in dependence on the external magnetic field.
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Electrotransport properties of the nanostructures fabricated by the FIB
Ostřížek, Petr ; Kolíbalová, Eva (referee) ; Urbánek, Michal (advisor)
The aim of this work is fabrication of nanostructures and measurement of their electrotransport properties. There are two different methods used for fabrication - electron beam lithography with sputtering of thin films and focused ion beam with deposition from gas phase. I-V characteristic was measured for characterisation of as prepared nanostructures - wires. Material of wires prepared by using of electron beam lithography was permalloy - an alloy of iron and nickel. Second types of wires prepared by using of chemical vapor deposition induced by focused ion beam was platinum based.
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Advanced techniques of micro- and nanosystems fabrication for sensors
Márik, Marian ; Pekárek, Jan (referee) ; Hubálek, Jaromír (advisor)
The use of micro- and nanotechnologies is necessary in the development of advanced sensor systems. In this thesis few selected technologies were studied and tested on fabrication of creating two different systems for bioelectrical and electrochemical applications. For biolelectrical applications a chip with a pair of gold nanoelectrodes was designed and implemented. For electrochemical analysis a novel two electrode system was designed and realized, which should contribute by greater sensitivity and accuracy in amperometric detection compared with three-electrode systems in voltammetric analysis. The fabricated systems were tested and the results were discussed.
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Testing of the new UHV scanning electron microscope and design of its effusion cel
Šárközi, Rudolf ; Mach, Jindřich (referee) ; Bábor, Petr (advisor)
This work focus on the development and the design of the effusion cell that is able to deposit different materials in downward orientation. The Cell itself should be placed into the ultra-vacuum microscope (UHV-SEM) developed in TESCAN company in the collaboration with Institute of Physical Engineering. Theoretical part is devoted to the description of the electron microscope and its, in the future installed, parts, which will be used for the preparation and the analysis of the nanostructures. In this work, the first measurements with the electron microscope are presented, and the influence of mechanical vibrations to image quality is discussed.
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Interaction of a SNOM tip with electromagnetic near-field produced by interference of surface plasmon polaritons
Jakub, Zdeněk ; Břínek, Lukáš (referee) ; Dvořák, Petr (advisor)
The aim of this bachelor’s thesis is fabrication of probes for scanning near-field optical microscope (SNOM) and testing of their functionality by measuring interference patterns of surface plasmon polaritons (SPP). The theoretical part deals with the basic properties of SPP’s and methods of their excitation and detection. In the experimental part, methods of sharp tip fabrication by chemical etching, thin film deposition by ion beam sputtering (IBS) or by ion beam assisted deposition (IBAD) and aperture opening by focused ion beam (FIB) are explained and demonstrated. Finally, interference patterns of SPP’s are measured with fabricated probes and the results are compared with the results obtained with commercially available probes.
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Determination of mechanical properties from microcompression test
Truhlář, Michal ; Kruml, Tomáš ; Kuběna, Ivo ; Petráčková, Klára ; Náhlík, Luboš
This paper describes a microcompression test of Al - 1.5 wt. % Cu thin film deposited on Si substrate. Microcompression combines the sample preparation with the use of ion focused beam (FIB) with a compression test carried out using nanoindenter. Cylindrical specimens (pillars) were prepared using FIB. The diameter of pillars was about 1.3 μm and their height was about 2 μm (equal to the film thickness). Stress-strain curves of the thin film were obtained. The results depend on crystallographic orientation of pillar. The paper is focused to an attempt to determine as precisely as possible Young modulus of the film using experimental data and finite element modelling.
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Estimation of mechanical properties of thin Al surface layer
Petráčková, Klára ; Kuběna, Ivo ; Truhlář, Michal ; Náhlík, Luboš ; Kruml, Tomáš
The paper describes a new method for testing of thin layers, so-called microcompression test. As an example determination of Al thin film properties deposited on Si substrate is introduced in the paper. Microcompression combines the sample preparation with the use of focused ion beam (FIB) with a compression test carried out using nanoindenter. Cylindrical specimens (pillars) were prepared in Al film using FIB. The typical diameter of pillars was about 1.3 μm and their height was about 2 μm. The results depend on crystallographic orientation of pillar. Stress-strain curves of the thin film were obtained. Experimentally measured data on pillars needs correction to obtain undistorted material properties of Al thin film. A necessary correction using finite element modeling is suggested in the paper. The paper contributes to a better characterization of very thin surface layers and determination of their mechanical properties.
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Mechanical properties of Al thin films measured by microcompression
Kuběna, Ivo ; Kruml, Tomáš
Two modern experimental techniques, the focused ion beam milling and the nanoindentation, were applied in order to measure exactly plastic properties of a Al-1.5%Cu thin film prepared by the physical vapour deposition, used for electrical connection of integrated circuits. By focused ion beam milling, cylindrical specimens were prepared. The height of the specimens was equal to the film thickness (2 micrometers) and their diameter was about 1.3 micrometers. These specimens were subjected to the compressive loading using the nanoindenter equipped by a flat punch. It is possible to obtain stress-strain curves of the thin film rather precisely.
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Nanocompression of oriented pillars from Al thin film
Kuběna, Ivo ; Kruml, Tomáš
In this paper, a new method of measurement of mechanical properties of thin films is presented. This method combines specimen preparation by focused ion beam (FIB) and compression test using nanoindentation device. Compression specimens were prepared from thin film, Al-1.5%Cu, which is commonly used in integrated circuit. Cylindrical specimens were prepared by FIB milling. The height of specimens (pillars) was about 2 mircrometers (equal to the film thickness) and their diameter was about 1.3 micrometers. The pillars are single crystalline, therefore the results depend on crystallographic orientation of pillar, which was specified by EBSD (electron backscatter diffraction). Stress-strain curves of the thin film were obtained in two representations.
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