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

Zenodo (CERN European Organization for Nuclear Research)

Abstract

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°

Authors 4

1. Achim Strauch Aachen 2nd Institute of Physics

   RWTH Aachen University · Forschungszentrum Jülich · Ernst Ruska Centre

   Affiliation as printed

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425 Jülich, Germany; 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany

2. Dieter Weber

   Forschungszentrum Jülich · Ernst Ruska Centre

   Affiliation as printed

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425 Jülich, Germany

3. Alexander Clausen

   Forschungszentrum Jülich · Ernst Ruska Centre

   Affiliation as printed

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425 Jülich, Germany

4. Knut Müller‐Caspary Aachen 2nd Institute of Physics

   RWTH Aachen University · Forschungszentrum Jülich · Ernst Ruska Centre

   Affiliation as printed

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425 Jülich, Germany; 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany