4 Pages

The effects of stray gun scattering in a commercial FEGTEM and its practical removal

ABSTRACT: We report the results of a preliminary study of the effects of stray scattering from the gun assembly in a FEI CM200 field emission transmission electron microscope. The uncollimated signal contributes to the electron energy loss (EEL) spectrum, most noticeably in spatially resolved spectra from small sample volumes such as interfaces as well as “aloof beam” measurements designed to maximise surface excitations. We have parameterised such effects in terms of experimental gun parameters and also present strategies for their removal during routine EELS analysis.