Atomic-level detection by X-ray microanalysis in the analytical electron microscope

摘要: Abstract Experimental measurements and calculations have demonstrated the detecton of 2 atoms, feasibility detecting single in analysis volume thin specimens using X-ray energy-dispersive spectrometry (XEDS). The use a 300 kV VG HB 603 field-emission gun analytical electron microscope, with highest possible collection efficiency is required. Experiments only available thin-film standard (NIST reference material 2063) indicate that, even when seeking relatively high atomic number elements low matrix, specimen thickness (101 nm this case) limits attempts to detect atoms. Comparison simulated experimental spectra confirm need for (∼10 nm) validity Goldstein–Romig–Michael equation defining detection limit. Using 10 nm foils homogenized Cu–0.12 wt% Mn alloys it shown that 2 Mn atoms can be achieved 99% confidence principal instrumental factor controls limit XEDS detector count rate rather than resolution.