Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-05-06T12:51:48.431Z Has data issue: false hasContentIssue false

Computationally Efficient Handling of Partially Coherent Electron Sources in (S)TEM Image Simulations via Matrix Diagonalization

Published online by Cambridge University Press:  15 September 2022

Zhongbo Li*
Affiliation:
Electron Microscopy Group of Materials Science, University of Ulm, Ulm 89081, Germany
Harald Rose
Affiliation:
Electron Microscopy Group of Materials Science, University of Ulm, Ulm 89081, Germany
Jacob Madsen
Affiliation:
Faculty of Physics, University of Vienna, Vienna 1090, Austria
Johannes Biskupek
Affiliation:
Electron Microscopy Group of Materials Science, University of Ulm, Ulm 89081, Germany
Toma Susi
Affiliation:
Faculty of Physics, University of Vienna, Vienna 1090, Austria
Ute Kaiser
Affiliation:
Electron Microscopy Group of Materials Science, University of Ulm, Ulm 89081, Germany
*
*Corresponding author: Zhongbo Li, E-mail: zhongbo.lee@uni-ulm.de
Get access

Abstract

We introduce a novel method to improve the computational efficiency for (S)TEM image simulation by employing matrix diagonalization of the mixed envelope function (MEF). The MEF is derived by taking the finite size and the energy spread of the effective electron source into account, and is a component of the transmission cross-coefficient that accounts for the correlation between partially coherent waves. Since the MEF is a four-dimensional array and its application in image calculations is time-consuming, we reduce the computation time by using its eigenvectors. By incorporating the aperture function into the matrix diagonalization, only a small number of eigenvectors are required to approximate the original matrix with high accuracy. The diagonalization enables for each eigenvector the calculation of the corresponding image by employing the coherent model. The individual images are weighted by the corresponding eigenvalues and then summed up, resulting in the total partially coherent image.

Type
Original Article
Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of the Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Allen, LJ & Findlay, S (2015). Modelling the inelastic scattering of fast electrons. Ultramicroscopy 151, 1122.CrossRefGoogle ScholarPubMed
Barthel, J (2018). Dr. Probe: A software for high-resolution STEM image simulation. Ultramicroscopy 193, 111.CrossRefGoogle ScholarPubMed
Bonevich, JE & Marks, LD (1988). Contrast transfer theory for non-linear imaging. Ultramicroscopy 26, 313319.CrossRefGoogle Scholar
Born, M & Wolf, E (1970). Principles of Optics. Oxford, UK: Pergamon Press.Google Scholar
Brown, H, Pelz, P, Ophus, C & Ciston, J (2020). A python based open-source multislice simulation package for transmission electron microscopy. Microsc Microanal 26, 29542956.CrossRefGoogle Scholar
Caramazza, S, Marini, C, Simonelli, L, Dore, P & Postorino, P (2016). Temperature dependent EXAFS study on transition metal dichalcogenides MoX2 (X= S, Se, Te). J Phys Condens Matter 28, 325401.CrossRefGoogle Scholar
Chang, L, Meyer, R & Kirkland, A (2005). Calculations of HREM image intensity using Monte Carlo integration. Ultramicroscopy 104, 271280.CrossRefGoogle ScholarPubMed
Cowley, JM & Moodie, AF (1957). The scattering of electrons by atoms and crystals. I. A new theoretical approach. Acta Crystallogr 10, 609619.CrossRefGoogle Scholar
DaCosta, LR, Brown, HG, Pelz, PM, Rakowski, A, Barber, N, O'Donovan, P, McBean, P, Jones, L, Ciston, J, Scott, M & Ophus, C (2021). Prismatic 2.0–Simulation software for scanning and high resolution transmission electron microscopy (STEM and HRTEM). Micron 151, 103141.Google Scholar
Dwyer, C (2005). Multislice theory of fast electron scattering incorporating atomic inner-shell ionization. Ultramicroscopy 104, 141151.CrossRefGoogle ScholarPubMed
Fertig, J & Rose, H (1981). Resolution and contrast of crystalline objects in high-resolution scanning transmission electron microscopy. Optik 59, 407429.Google Scholar
Forbes, B, Martin, A, Findlay, SD, D'Alfonso, AJ & Allen, LJ (2010). Quantum mechanical model for phonon excitation in electron diffraction and imaging using a Born-Oppenheimer approximation. Phys Rev B 82, 104103.CrossRefGoogle Scholar
Frank, J (1973). The envelope of electron microscopic transfer functions for partially coherent illumination. Optik 38, 519.Google Scholar
Gong, H (1994). Theory and computation for imaging in scanning transmission microscopy considering partial coherence in illumination. Ultramicroscopy 55, 373381.CrossRefGoogle Scholar
Harada, J & Pedersen, T (1968). Debye-Waller factors of tetragonal barium titanate. J Phys Soc Japan 25, 14131418.Google Scholar
Hawkes, P (1978). Coherence in electron optics. Adv Opt Electron Microsc 7, 101184.Google Scholar
Hosokawa, F, Shinkawa, T, Arai, Y & Sannomiya, T (2015). Benchmark test of accelerated multi-slice simulation by GPGPU. Ultramicroscopy 158, 5664.CrossRefGoogle ScholarPubMed
Ishizuka, K (1980). Contrast transfer of crystal images in TEM. Ultramicroscopy 5, 5565.CrossRefGoogle Scholar
Ishizuka, K (2022). xHREM: HREM simulation suite. Available at https://www.hremresearch.com/xhrem/Google Scholar
Kirkland, EJ (1998). Advanced Computing in Electron Microscopy. New York: Plenum Press.CrossRefGoogle Scholar
Kirkland, EJ (2016). Computation in electron microscopy. Acta Crystallogr A 72, 127.Google ScholarPubMed
Kirkland, EJ, Loane, RF & Silcox, J (1987). Simulation of annular dark field STEM images using a modified multislice method. Ultramicroscopy 23, 7796.CrossRefGoogle Scholar
Koch, C (2010). QSTEM: Quantitative TEM/STEM simulations. Available at https://www.physik.hu-berlin.de/en/sem/software/software_qstemGoogle Scholar
Kohl, H & Rose, H (1985). Theory of image formation by inelastically scattered electrons in the electron microscope. In Advances in Electronics and Electron Physics, Vol. 65, pp. 173–227. Cambridge, US: Elsevier.CrossRefGoogle Scholar
Lee, Z, Hambach, R, Kaiser, U & Rose, H (2017). Significance of matrix diagonalization in modelling inelastic electron scattering. Ultramicroscopy 175, 5866.CrossRefGoogle ScholarPubMed
Lee, Z, Lehnert, T, Kaiser, U & Rose, H (2019). Comparison of different imaging models handling partial coherence for aberration-corrected HRTEM at 40–80 kV. Ultramicroscopy 203, 6875.CrossRefGoogle ScholarPubMed
Lobato, I, Van Aert, S & Verbeeck, J (2016). Progress and new advances in simulating electron microscopy datasets using MULTEM. Ultramicroscopy 168, 1727.CrossRefGoogle ScholarPubMed
Madsen, J & Susi, T (2020). abTEM: Ab initio transmission electron microscopy image simulation. Microsc Microanal 26, 448450.CrossRefGoogle Scholar
Müller, H, Rose, H & Schorsch, P (1998). A coherence function approach to image simulation. J Microsc 190, 7388.CrossRefGoogle Scholar
Nellist, P & Rodenburg, J (1994). Beyond the conventional information limit: The relevant coherence function. Ultramicroscopy 54, 6174.CrossRefGoogle Scholar
Noll, RJ (1976). Zernike polynomials and atmospheric turbulence. J Opt Soc Am 66, 207211.CrossRefGoogle Scholar
Oelerich, JO, Duschek, L, Belz, J, Beyer, A, Baranovskii, SD & Volz, K (2017). STEMsalabim: A high-performance computing cluster friendly code for scanning transmission electron microscopy image simulations of thin specimens. Ultramicroscopy 177, 9196.CrossRefGoogle ScholarPubMed
O'Keefe, M & Buseck, P (1979). Computation of high resolution TEM images of minerals. Trans ACA 15, 2746.Google Scholar
Ophus, C (2017). A fast image simulation algorithm for scanning transmission electron microscopy. Adv Struct Chem Imaging 3, 111.Google ScholarPubMed
Pelz, PM, Rakowski, A, DaCosta, LR, Savitzky, BH, Scott, MC & Ophus, C (2021). A fast algorithm for scanning transmission electron microscopy (STEM) imaging and 4D-STEM diffraction simulations. Microsc Microanal 27, 835-848.Google Scholar
Peng, LM, Ren, G, Dudarev, S & Whelan, M (1996). Debye–Waller factors and absorptive scattering factors of elemental crystals. Acta Crystallogr A 52, 456470.CrossRefGoogle Scholar
Pulvermacher, H (1981). Transmission cross-coefficient for electron microscopic imaging with partially coherent illumination and electric instability. Optik 60, 45.Google Scholar
Radek, M, Tenberge, JG, Hilke, S, Wilde, G & Peterlechner, M (2018). STEMcl—A multi-GPU multislice algorithm for simulation of large structure and imaging parameter series. Ultramicroscopy 188, 2430.CrossRefGoogle ScholarPubMed
Röder, F & Lubk, A (2014). Transfer and reconstruction of the density matrix in off-axis electron holography. Ultramicroscopy 146, 103116.CrossRefGoogle ScholarPubMed
Rose, H (1976). Image formation by inelastically scattered electrons in electron microscopy. Optik 45, 139158.Google Scholar
Rose, H (1984). Information transfer in transmission electron microcopy. Ultramicroscopy 15, 173191.CrossRefGoogle Scholar
Rosenauer, A & Schowalter, M (2008). STEMSIM—A new software tool for simulation of STEM HAADF Z-contrast imaging. Microscopy of Semiconducting Materials 2007, pp. 170–172. Dordrecht: Springer.CrossRefGoogle Scholar
Saxton, WO (1977). Spatial coherence in axial high resolution conventional electron microscopy. Optik 49, 51.Google Scholar
Schattschneider, P, Nelhiebel, M & Jouffrey, B (1999). Density matrix of inelastically scattered fast electrons. Phys Rev B 59, 10959.CrossRefGoogle Scholar
Singh, S & De Graef, M (2018). GPU-accelerated matrix exponentiation for 5-D STEM-DCI simulations. Microsc Microanal 24, 222223.CrossRefGoogle Scholar
Stadelmann, P (2021). JEMS-EMS java version. Available at https://www.jems-swiss.ch/Google Scholar
Van den Broek, W, Jiang, X & Koch, C (2015). FDES, a GPU-based multislice algorithm with increased efficiency of the computation of the projected potential. Ultramicroscopy 158, 8997.Google ScholarPubMed
Verbeeck, J, Schattschneider, P & Rosenauer, A (2009). Image simulation of high resolution energy filtered TEM images. Ultramicroscopy 109, 350360.CrossRefGoogle ScholarPubMed
Wade, RH & Frank, J (1977). Electron microscope transfer functions for partially coherent axial illumination and chromatic defocus spread. Optik 49, 81.Google Scholar
Wentzel, G (1926). Zwei Bemerkungen über die Zerstreuung korpuskularer Strahlen als Beugungserscheinung. Z Phys 40, 590593.CrossRefGoogle Scholar
Yao, Y, Ge, B, Shen, X, Wang, Y & Yu, R (2016). STEM image simulation with hybrid CPU/GPU programming. Ultramicroscopy 166, 18.CrossRefGoogle ScholarPubMed