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Auger electron spectro-microscopy
Hrnčiřík, Petr
The short escape depth of Auger electrons, the high lateral resolution, the chemical information about superficial elemental composition and the possibility of measuring the indepth distribution of elements (with utilisation of the ion sputtering) are the main advantages of the Auger electron spectroscopy (AES). When combined with the scanning electron miscroscope, AES can provide with image signal suitable for spectro-micrographs showing distribution of elements over the surface, i.e. the chemical mapping. This mapping can be advantageously compared with other SEM image signals in order to faciliate their interpretation.
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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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Rastrovací elektronová mikroskopie pomalými elektrony
Hrnčiřík, Petr ; Müllerová, Ilona
Největší možná tloušťka vzorku pro prozařovací elektronovou mikroskopii (TEM) je ovlivněna nepružnou a pružnou střední volnou dráhou (IMFP a EMFP). Při energiích běžně používaných v transmisní elektronové mikroskopii (>50 keV), obě střední volné dráhy se snižují s klesající energií primárního svazku. Proniknout dostatečně vzorkem dané tloušťky je potom pouze otázkou použití dostatečně vysoké energie primárních elektronů. Pokud je energie primárních elektronů snížena pod 100 eV, IMFP se opět zvyšuje. Toto otevírá možnost prozařovací elektronové mikroskopie pomalými elektrony, s nižším rozlišením ale velmi sníženým radiačním poškozením vzorku
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