Lorentz scanning transmission electron microscopy (Lorentz STEM) : Influence of the electron beam cross-sectional profile on the detector performance

摘要

Lorentz scanning transmission electron microscopy (Lorentz STEM), a technique to observe magneticand electric field distributions in microscopic region, is performed by detecting the position of a beam spotformed on the detector. Since the shift of the spot reflects Lorentz force imposed by the field on the electronbeam, accuracy of the observed field distributions depends much on the detector performance in locating thespot position. A numerical model has been used to examine how the profile of the beam spot on the detectoraffects the detector outputs. Results indicate that the beam spot with non-circular profile would cause signaluncertainty that defies quantitative analyses.