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Kontrast zrn na velmi nízkých energiích v REM
Pokorná, Zuzana ; Frank, Luděk
When lowering energy of incident electrons to 100 eV and less, the elastic scattering becomes heavily anisotropic while the inelastic scattering progressively drops off. Energy dependence of the reflected signal becomes then specific to the crystal orientation. The experiments with the imaging of the metal polycrystals were done in the SEM equipped by the cathode lens.
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Charakterizace mikrostrtuktury kvazikrystalického aproximantu Al77,5Cr16,5Fe6
Svoboda, Milan ; Buršík, Jiří ; Janovec, J. ; Dolinšek, J.
Characterisation of the quasicrystalline approximant in Al77,5Cr16,5Fe6 alloy is the main aim of this work. The characterisation was performed by transmission electron microscopy,electron diffraction,scanning electron microscopy and energy dispersive X-ray spectroscopy. By using those methods we have identified 2 phases differing each other especially by content of iron.
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Zdokonalení monokrystalických scintilátorů pro scintilační detektory v S(T)EM
Schauer, Petr
Scintillator is a problematic part of any scintillation detector for S(T)EM. The reason lies in its decay time and especially in its afterglow, which deteriorate the ability to transfer image contrast. In other words, a slow scintillator causes a bad modulation transfer function (MTF) of the whole detector. If a series of alternating white and black points is transferred using such a scintillator, the image is somewhat degraded at the typical S(T)EM spatial frequency. To enhance the MTF of the detector, the kinetics of the cathodoluminescence (CL) of many single crystal scintillators has been studied at our laboratory. Some results concerning single crystals of cerium-activated yttrium aluminum garnet (YAG:Ce) and cerium-activated yttrium aluminum perovskite (YAP:Ce) are presented in this paper.
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Analýza poly[methyl(phenyl)silylene] degradovaného elektronovým svazkem
Horák, Petr ; Schauer, Petr
Polysilanes (PSi) are a broad class of organic materials whose basic building block is a chain built up of silicon. The susceptibility to material degradation is a characteristic property of PSi. PSi are degradable for example by ultraviolet radiation or by electron beam. The degradation of the material decreases intensity of luminescence. Poly[methyl(phenyl)silylene] (PMPSi) was selected as a typical representative of PSi.
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Dynamické chování kontrastu dopantů v LVSEM
Mika, Filip ; Frank, Luděk
Contrast between differently doped areas in semiconductors can be observed in the secondary electron emission in a scanning electron microscope. Behaviour of the contrast in dependence on the incident electron dose and energy and on the presence of surface adlayers has been studied on different doped samples.
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Optimalizace detekce sekundárních elektronů segmentovým ionizačním detektorem v environmentálním REM
Černoch, P. ; Jirák, Josef
The article deals with a prezentation of results of optimization of secondary electron detection by an ionization detector in the environmental scanning electron microscope. The ionization detectors consisting of a varied electrode geometry and varied voltages on these electrodes, named segmental ionization detectors, are presented as a possibility to reach desired contrasts in a specimen image. In this work, images acquired by several detectors demonstrate detection of different types of signal electrons utilizing a specimen containing thin surface layers and a specimen made for a material contrast measurement.
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CAD v elektronové optice
Lencová, Bohumila
Invited talk on 8th Multinational congress on microscopy in the session Electron optics and optical elements. It discusses the themes of reduced interest in papers from electron optics on microscopy conferences and the progress in computational programs (such as EOD from ISI AS CR), in particular in accurate electron ray tracing in electromagnetic fields and in user interfaces.
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