Origin of triangular artifacts at strongly scattering lead columns

Determine the precise origins of the triangular artifacts observed at strongly scattering Pb columns in multislice electron ptychography reconstructions of phase-only objects, including whether they arise from strong elastic scattering or from a reconstruction artifact.

Background

The paper reconstructs phase-only 4D-STEM simulations of 29 nm thick SrTiO3 and PbTiO3 specimens to distinguish amplitude contrast caused by elastic multiple scattering from amplitude contrast caused by attenuation of the coherent elastic signal through thermal scattering. These phase-only reconstructions recover negligible amplitude contrast, but they exhibit triangular artifacts at strongly scattering Pb columns, whereas lower-Z columns remain approximately round.

The authors do not resolve whether these triangular features originate from the strong scattering associated with Pb columns or from the reconstruction procedure itself. This uncertainty is relevant to interpreting non-ideal reconstructed phase structure in multislice electron ptychography, particularly for heavy-element columns.

References

The precise origins are unclear, but may result from the strong scattering at these columns or as an artifact of reconstruction.

— On Transmission Function Amplitude and Phase Recovery in Multislice Electron Ptychography  (2608.21007 - Denzer et al., 21 Aug 2026) in Section 3.2, “Origins of the Reconstructed Phase and Amplitude Contrast”