High resolution X-ray mapping in the STEM

Current commercial analytical electron microscopes (AEMs) are a compromise design between the highest spatial, analytical and energy resolutions. By using such modern AEMs, quantitative X-ray mapping becomes achievable, while maintaining high spatial resolution (the original aim of such instruments). However, there is now the possibility of combining the best aspects of currently available instruments with new developments in computer control, spherical aberration correction, and high energy resolution X-ray detectors to produce the ideal AEM, offering atomic-level spatial resolution, atomic-level detection limits, and energy resolutions of a few eV. In addition to the new instrumentations, a new quantification technique for thin specimens is now available. This paper reviews the current state of AEM X-ray microanalysis and the steps needed to attain these ideal, high-resolution, parameters, and then describes the progress towards achieving them.