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Morphology study of organic molecular compounds thin films
Schön, Martin ; Vala, Martin (referee) ; Salyk, Ota (advisor)
This thesis deals with morphology study of organic molecular thin film compounds. The vapour deposition was used for thin films preparation. There are described used vacuum technology and measuring instruments in the theoretical part. In the second part is then described the experiment. The characteristics and morphology of thin films have been analyzed by scanning electron microscope (SEM). Influence of deposition temperature and distance between substrate holder and evaporator boat on film morphology have been analyzed. Diketopyrrolopyrrole (DPP) thin films have interesting chemical and physical properties, expecting wide range of applications, especially in electronics industry.
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The insoluble particles in water deposited from fog at Milešovka Observatory (Czech Republic)
Bartůňková, Kristýna ; Fišák, Jaroslav ; Stoyanova, V. ; Schoumkova, A.
This study concerns insoluble chemical pollution of fog at Milešovka Observatory in the Czech Republic. In period from August 2006 till July 2007, 25 fog samples at the top of Milešovka Mountain in České Středohoří Mountains were collected by active fog water collector. Water samples were filtered. From 53 to 116 particles from every sample were chosen according to the quantity of particles found in dried filters. Altogether it was more than 2000 particles. Particles were examined with the help of Scanning Electron Microscope and Energy Dispersive X-Ray Spectrometer to distinguish sizes, shapes and composition. After analyzing the data, statistical evaluation was made. Particles were put into categories according to their shapes on spherical and not spherical. Typical particles like Al, Si, K, Fe or Ca-rich particles were determined. Focus was also to particles with rarely represented elements like Ni, Au, Pb, Cu, Zr and Ba. Groups of typical insoluble particles were collated according to meteorological conditions - synoptic situations and wind directions which prevailed in the days of fog events in order to try to find out possible sources of this fog pollution.
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Freezy sublimation in cryoattachement Gatan Alto 2500 connected to scanning electron microscope JSM-7401F
MAROUŠEK, Roman
This thesis deals with freezy sublimation in cryoattachement Gatan Alto 2500 connected to scanning electron microscope (SEM) JEOL JSM-7401F. The thesis is devided into the theoretical and practical parts. In the theoretical part I focus mainly on physical qualities of water and on problematics of freezy-drying. I also describe qualities of subsidiary substances which are being used when working with cryotechnology. I briefly describe technology used: cryoattachement Alto 2500 and SEM JSM-7401F. In the practical part I deal with the description of the method that I have developed in order to measure weight decrease of frozen specimen owning to its sublimation in vacuum. I provide measurement results of the sublimation of these substances: demineralized water, Dextran, glycerol and phosphate buffer saline.
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Prevence tvorby uhlovodíkové kontaminace v SEM
Dvořáková, Marie ; Mika, Filip
Electron beam-induced contamination is one of the most undesirable effects in SEM. In this work the contamination was formed on silicon wafer, copper, aluminium, stainless plate and nickel samples. The contamination was removed by the plasma cleaning (XEI Scientific Evactron De-Contaminator).
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Adaptation of scanning electron microscope to environmental scanning electron microscope
Neděla, Vilém
This paper deals with adaptation of the scanning electron microscope (SEM) to the environmental scanning electron microscope (ESEM). It focuses especially to the construction and assembly of the differential pumping chamber together with the detector board of the differential pumping chamber and it comments reasons of necessity of the assembly of these parts in the environmental scanning electron microscope.
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Computer controlled SEM with Schottky cathode for imaging in slow and Auger electrons
Hrnčiřík, Petr ; Müllerová, Ilona
The ultrahighvacuum Scanning Electron Microscope has been built using the column of an old prototype (later produced as Tesla BS 350), some spare parts for BS 350 and new components, including computer controlled electronics. The whole vacuum system was extensively reconstructed, too. The Schottky cathode was introduced into the microscope instead of the original cold field emission gun. The advantage of this system includes a high current density, higher stability and lower vacuum demands at comparable performance as regards the resolution. Therefore it is possible to practice surface analysis with Auger electrons at a high resolution. The microscope was also adapted to the operation with slow and very slow electrons, again at high resolution, so that these two methods can be in situ compared.
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The possibilities of using FFT for rating the quality of detected signal in ESEM
Přichystal, Vladimír
The main demand for processing of images from scanning electron microscope is acquirement of the best quality of raster image and description of attributes of micrographs and possibility of their comparison with other micrographs. Therefore software was compiled, which serves to numerical calculation of the Fast Fourier Transform (FFT) of micrographs, evaluation and development of their quality.
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