Application of 80-200 kV aberration corrected dedicated STEM with cold FEG

Abstract

We have developed new STEM instrumentation with a cold field emission source (Hitachi HD-2700) in order to perform structural characterization and elemental mapping at the atomic level. The instrument utilises the CEOS GmbH (Germany, managing director: Dr. Max Haider) aberration corrector. The accelerating voltage range is between 80 kV and 200 kV. The cold field emission source proves to be the ideal emitter for analytical transmission electron microscopes due to its high brightness, high current density and small energy spread. In this study, we have examined low accelerating voltage conditions for obtaining high image contrast and high performance elemental analysis (in which FWHM of zero loss peaks are 0.3 eV for acquisition time of 1 second and 0.34 eV for acquisition time of 40 second by accelerating voltage of 80 kV, respectively). We have observed high contrast bright field STEM images of graphene carbon at an accelerating voltage of 80 kV, in which lattice fringes can be clearly seen. © 2010 IOP Publishing Ltd.