The resolution limit for elemental mapping in energy-filtering transmission electron microscopy

In recent years electron microscopes with energy filtering devices have found widespread acceptance. Combined with an effective detection system, such as a slow-scan CCD camera, these microscopes allow the rapid acquisition of elemental maps of large areas. Due to the low cross-sections for the relevant inner-shell excitations, the resolution attainable with a given object is limited by the signal-to-noise ratio. We shall propose a resolution criterion which includes the statistical properties of the images and discuss the dependence of this “object resolution limit” on instrumental parameters.