摘要
A fast,robust pipeline for strain mapping of crystalline materials is important for many technological applications.Scanning electron nanodiffraction allows us to calculate strain maps with high accuracy and spatial resolutions,but this technique is limited when the electron beam undergoes multiple scattering.Deep-learning methods have the potential to invert these complex signals,but require a large number of training examples.We implement a Fourier space,complex-valued deep-neural network,FCU-Net,to invert highly nonlinear electron diffraction patterns into the corresponding quantitative structure factor images.FCU-Net was trained using over 200,000 unique simulated dynamical diffraction patterns from different combinations of crystal structures,orientations,thicknesses,and microscope parameters,which are augmented with experimental artifacts.We evaluated FCU-Net against simulated and experimental datasets,where it substantially outperforms conventional analysis methods.Our code,models,and training library are open-source and may be adapted to different diffraction measurement problems.
基金
This work was primarily funded by the US Department of Energy in the program“4D Camera Distillery:From Massive Electron Microscopy Scattering Data to Useful Information with AI/ML.”
M.K.Y.C.and C.O.each acknowledge support of a US Department of Energy Early Career Research Award
J.C.acknowledges support from the Presidential Early Career Award for Scientists and Engineers(PECASE)through the U.S.Department of Energy.B.H.S.and py4DSTEM development are supported by the Toyota Research Institute
S.E.Z.was supported by the National Science Foundation under STROBE Grant no.DMR 1548924
Work at the Molecular Foundry was supported by the Office of Science,Office of Basic Energy Sciences,of the US Department of Energy under Contract No.DE-AC02-05CH11231
Use of the Center for Nanoscale Materials,an Office of Science user facility,was supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Contract No.DE-AC02-06CH11357
This research used resources of the National Energy Research Scientific Computing Center,a DOE Office of Science User Facility supported by the Office of Science of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231。
