Research Highlights

GaN atomic electric fields from a segmented STEM detector: Experiment and simulation

Tim Grieb; Florian F. Krause; Thorsten Mehrtens; Christoph Mahr; Beeke Gerken; Marco Schowalter; Bert Freitag; Andreas Rosenauer

Journal of Microscopy   (2024)

Atomic electric fields in a thin GaN sample are measured with the centre-of-mass approach in 4D-scanning transmission electron microscopy (4D-STEM) using a 12-segmented STEM detector in a Spectra 300 microscope. The electric fields, charge density and potential are compared to simulations and an experimental measurement using a pixelated 4D-STEM detector. The segmented detector benefits from a high recording speed, which enables measurements at low radiation doses. However, there is measurement uncertainty due to the limited number of segments analysed in this study.

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