FACTORS LIMITING THE SPATIAL-RESOLUTION AND SENSITIVITY OF EELS MICROANALYSIS IN A STEM

The experimental parameters which limit the spatial resolution and sensitivity of parallel electron-energy-loss microanalysis have been reviewed in order to determine the limiting factors over a range of experimental conditions. The effects of the signal-detector characteristics and electron optics on the performance of the microanalytical technique have been quantified. The importance of statistical considerations (signal-to-noise ratios) and the specimen itself are considered in order to develop a non-arbitrary definition of microanalytical performance based not only on the electron beam dimensions, but also incorporating other experimental limitations.