Composition measurement in substitutionally disordered materials by atomic resolution energy dispersive X-ray spectroscopy in scanning transmission electron microscopy.
The increasing use of energy dispersive X-ray spectroscopy in atomic resolution scanning transmission electron microscopy invites the question of whether its success in precision composition determination at lower magnifications can be replicated in the atomic resolution regime. In this paper, we explore, through simulation, the prospects for composition measurement via the model system of AlxGa1-xAs, discussing the approximations used in the modelling, the variability in the signal due to changes in configuration at constant composition, and the ability to distinguish between different compositions. Results are presented in such a way that the number of X-ray counts, and thus the expected variation due to counting statistics, can be gauged for a range of operating conditions.
School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia.
Z
Z
Chen
School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia.
D J
DJ
Taplin
Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria 3800, Australia; Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia.
M
M
Weyland
School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
L J
LJ
Allen
School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia. Electronic address: scott.findlay@monash.edu.
S D
SD
Findlay
Atomic-resolution imaging; Elemental quantification; Energy dispersive X-ray spectroscopy (EDX); Scanning transmission electron microscopy (STEM)