The 4D Camera – An 87 kHz Frame-rate Detector for Counted 4D-STEM Experiments

Fast Grain Mapping with Sub-Nanometer Resolution Using 4D-STEM with Grain Classification by Principal Component Analysis and Non-Negative Matrix Factorization

“…Developments in direct-electron detector technology continue to transform the field, with data acquisition speeds greater than ten thousand frames per second now realized (Ercius et al, 2020; Nord et al, 2020), that is, two orders of magnitude faster than the direct-electron detector used in this work. With this significant advance, 4D-STEM is now poised to enable efficient grain mapping over fields of view approaching the sizes surveyed by EBSD in the SEM, but with the spatial resolution provided by STEM.…”

py4DSTEM: A Software Package for Four-Dimensional Scanning Transmission Electron Microscopy Data Analysis

“…The compression level achieved will vary with the individual dataset and depends strongly on dose. Lower dose data will contain electron strike events in a lower the fraction of pixels, and thus allow for greater compression; see also Nord et al (2020) and Ercius et al (2020). For the dataset shown in the figure, electron counting compresses the data by a factor of ∼6,000.…”

Imaging atomic motion of light elements in 2D materials with 30 kV electron microscopy

“…However, iDPC-STEM is considerably more suitable for dynamical phenomena studies than electron ptychography, due to its direct imaging and vast speed advantage, because the several solid-state electron detectors that iDPC-STEM employs are two to three orders of magnitude faster than electron detecting cameras used for electron ptychography and 4D STEM, although the speed of such camera detectors are expected to improve in the near future 42,43 . For instance, four image frames of 512 x 512 pixels are acquired in about 1 minute with iDPC-STEM in this work (and up to 100 times higher frame rates are readily possible), but take at least 35 minutes with 4D STEM, which additionally produce large datasets (68 GB versus 17 MB for iDPC-STEM) and require time consuming and complex reconstructions schemes for electron ptychography 24,25,44 . We note, however, that even the fastest iDPC-STEM acquisition of a reasonable field-of-view is limited to a frame time of 0.1-1.0 second, by no means fast enough for many physical phenomena occurring on shorter timescales.…”