Synthetic 4D STEM dataset based on a SrTiO3 supercell with two additional artificial spatial frequencies

This dataset allows to investigate phase contrast methods for 4D scanning transmission electron microscopy, such as ptychography. A synthetic dataset has been simulated, based on an SrTiO3 unit cell as a starting point. Then, a five by five super cell was created by repetition. Two artificial spatial frequencies were added to the phase grating, one with a wavelength of a single unit cell and one with a wavelength of the super cell. To eliminate dynamical scattering, a 4D-STEM simulation with 20 × 20 scan points per unit cell was performed using only one slice with a thickness of one unit cell along electron beam direction [001]. Files conf_01.mat: HDF5 file with the phase grating. Data extraction and plot of the phase grating.ipynb: Jupyter notebook showing how to access the phase grating file and plot the data. slice_00001_thick_1.9525_nm_blocksz100.raw: Simulated 4D STEM dataset as a raw binary file. Shape 100 x 100 x 596 x 596, dtype float32. ssb-example.ipynb: Jupyter notebook showing first moment analysis and ptychography with the dataset. Simulation parameters Scan points: 100x100 Field of view: 1.9525nm Convergence angle: 23mrad, 136 px Acceleration voltage: 300 kV Center: (297, 297) Rotation angle: 0°Achim Strauch and Knut Müller-Caspary were supported by funding from the Initiative and Network Fund of the Helmholtz Association (Germany) under contract VH-NG-1317 (moreSTEM project). Knut Müller-Caspary acknowledges support from Helmholtz within the project "Ptychography 4.0" under contract ZT-I-0025