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Automation and control of multilayers deposition by IBS/IBAD
Pavera, Michal ; Sobota, Jaroslav (referee) ; Urbánek, Michal (advisor)
This diploma thesis deals with the automation of the deposition process by ion beam sputtering and ion beam assisted deposition. This work contains drawings of mechanical adjustments of the deposition chamber designed to control shutter and rotation of the target using stepper motors. There are presented ways to control stepper motors and troubleshoot their exact settings. Another task is to design a system for computer control of the deposition process. There are discussed ways to control the ion sources, pressure meter, flow meter and thickness meter, and their connection to a PC via RS-232 and analog-digital converters. It is also designed control program in LabVIEW, which allow automated multilayer deposition. Last part of the thesis deals with testing automatic deposition and results are commented.
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Study of fracture toughness and wear resistance of thin MoBC coating under dynamic conditions
Buršíková, V. ; Grossman, Jan ; Fořt, Tomáš ; Souček, P. ; Zábranský, L. ; Buršík, Jiří ; Vašina, P. ; Dupák, Libor ; Sobota, Jaroslav
The aim of the present work was to study the mechanical properties of thin amorphous MoBC coatings and MoBC coatings consisting of nanocrystalline Mo2BC embedded in amorphous MoBC matrix. The hardness of the amorphous MoBC coatings (20 GPa) is comparable with the common amorphous diamond-like carbon coatings, however their elastic modulus as well as fracture toughness and ductility are significantly higher. Magnetron sputtering of three targets, B4C, C and Mo, for MoBC was used for coatings preparation. The aim of this work was to study the mechanical and tribological properties of MoBC coatings deposited on high speed steel substrate. The classification of MoBC coatings was performed using an impact tester in a dynamic mode and enabled us to predict the limit load causing the coating destruction.
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A Comparison of Different Measurement Method of Mechanical Properties of Al Thin Film
Truhlář, M. ; Buršíková, V. ; Sobota, Jaroslav ; Kruml, Tomáš
The paper compares two different methods for testing of metallic thin films: microcompression test and nanoindentation. Microcompression test is one possibility how to perform mechanical tests on a very small scale. This method requires preparation of a small cylindrical specimen (micropillar) of micrometric size by FIB and execution of a compression test using nanoindenter device equipped with a flat diamond punch. Stressstrain curves of the thin films were obtained from such tests. Nanoindentation tests were then conducted to compare the results on the same films. Two different metal thin films – AlCuW, AlCuSi with thickness 2 .mu.m and grain size 3.8 .mu.m in average were prepared by PVD method. In this paper, we announce the results of measurements, a comparison of the results obtained by each method and identify advantages and limitations of the methods.
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Radioisotope method of compound flow analysis
Petryka, L. ; Zych, M. ; Hanus, R. ; Sobota, J. ; Vlasák, Pavel ; Malczewska, B.
The paper presents gamma radiation application to analysis of a multicomponent or multiphase flow. Such information as a selected component content in the mixture transported through pipe is crucial in many industrial or laboratory installations. Properly selected sealed radioactive source and collimators, deliver the photon beam, penetrating cross section of the flow. Detectors mounted at opposite to the source side of the pipe, allow recording of digital signals representing composition of the stream. In the present development of electronics, detectors and computer software, a significant progress in know-how of this field may be observed. The paper describes application of this method to optimization and control of hydrotransport of solid particles and propose monitoring facilitating prevent of a pipe clogging or dangerous oscillations.
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Main Activites of the Institute of Scientific Instruments
Müllerová, Ilona ; Radlička, Tomáš ; Mika, Filip ; Krzyžánek, Vladislav ; Neděla, Vilém ; Sobota, Jaroslav ; Zobač, Martin ; Kolařík, Vladimír ; Starčuk jr., Zenon ; Srnka, Aleš ; Jurák, Pavel ; Zemánek, Pavel ; Číp, Ondřej ; Lazar, Josef ; Mrňa, Libor
Institute of Scientific Instruments (ISI) was established in 1957 to develop diverse instrumental equipment for other institutes of the Academy of Sciences. ISI has long experience in research and development of electron microscopes, nuclear magnetic resonance equipment, coherent optics and related techniques. Nowadays the effort concentrates on scientific research in the field of methodology of physical properties of matter, in particular in the field of electron optics, electron microscopy and spectroscopy, microscopy for biomedicine, environmental electron microscopy, thin layers, electron and laser beam welding, electron beam lithography using Gaussian and shaped electron beam, nuclear magnetic resonance and spectroscopy, cryogenics and superconductivity, measurement and processing of biosignals in medicine, non-invasive cardiology, applications of focused laser beam (optical tweezers, long-range optical delivery of micro- and nano-objects) and lasers for measurement and metrology. ISI works both independently and in cooperation with universities, other research and professional institutions and with private companies at national and international level.
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Dynamic impact tester of hard thin coatings
Grossman, Jan ; Dupák, Libor ; Fořt, Tomáš ; Sobota, Jaroslav
An impact test has been used to evaluate the impact wear resistance of nanostructured hard coatings using a system developed at the Institute of Scientific Instruments in collaboration with the Brno University of Technology. After the test, wear scars were evaluated by means of scanning electron microscope, spectral analyses and profilometer. The impact test offers an important new method for the determination of both the fracture toughness and wear behaviour of hard thin coatings.
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Influence of annealing to stress in CNx:(H) films observed by SLEEM
Mikmeková, Eliška ; Mikmeková, Šárka ; Müllerová, Ilona ; Sobota, Jaroslav
The effect of high residual stress on the quality of thin sputtered carbon nitride films has been studied by Scanning Low Energy Electron Microscopy (SLEEM). Basically, two different types of stress can be identified in thin films: compressive stress and tensile stress. Compressive stress leads to wrinkling and film delamination and tensile stress can cause the fracturing of thin films. Experiments were made in the Tescan TS 5130 MM equipped with the Cathode Lens system (CL), which enable us to observe samples at arbitrary landing energies of the illuminating electrons. Operating of a SEM at low energies offers several advantages: an increase of materials contrast via low energy, high ratio SE, BSE signal and noise, smaller interaction volume and elimination of charging effects. The effect of annealing in vacuum to residual stress (calculated from Stoney’s equation) was measured. The porous character of films was observed by thermal desorption spectroscopy (TDS).
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