Atomic-resolution element mapping by combination of energy-dispersive X-ray detector and aberration-correction electron microscope

Dr. C. H. Chen (National Taiwan University, Taiwan) and his colleagues recently published a report on ultra high resolution element mapping. The research group employed a scanning transmission electron microscope (STEM) with specially enhanced spherical aberration correction. The beam size was nearly 1 Å. A silicon drift detector (Bruker XFlash-5030) was employed and set with a solid angle of 0.13 steradian. The group studied InGaAs/InAlAs superlattices, and discussed the 1.47 Å dumbbell structure using both structural imaging and mapping of characteristic X-rays (In L, Ga K and As K). For more information, see the paper, "Emergent Chemical Mapping at Atomic-Column Resolution by Energy-Dispersive X-Ray Spectroscopy in an Aberration-Corrected Electron Microscope", M.-W. Chu et al., Phys. Rev. Lett. 104, 196101 (2010).