Atomic-Scale 3D Structure of Complex Nanomaterials via Electron P/tychography: Confined Phases and Algorithmic Developments

Electron ptychography — a computational phase-contrast method that reconstructs the sample’s transmission function from overlapping scanning-diffraction patterns — is rapidly becoming a practical tool for resolving the atomic structure of complex nanomaterials far beyond conventional depth-of-focus and coherence limits. For materials synthesis and nanoscale structure–property research, this capability opens a new window into interfaces, confined phases, defect networks, and metastable structural motifs that govern functional behavior.
We present three recent advances that make 3D ptychographic imaging broadly applicable to real nanomaterials systems. First, using tomographic 4D-STEM tilt-series acquisition, we resolve the atomic lattice of a Zr–Te phase confined in double-wall carbon nanotubes, demonstrating that ptychographic single-slice tomography can identify intricate polytypes and nanoscale structural distortions relevant to templated growth. Second, a multi-slice reconstruction coupled with joint tomographic alignment overcomes the depth-of-focus barrier, enabling atomic resolution across tens of nanometers of heterogeneous material and allowing quantitative mapping of stacking variations, strain fields, and local bonding distortions that arise during synthesis.
Third, we introduce an end-to-end reconstruction framework — incorporating multi-slice propagation, partial coherence, position/Euler alignment, and compressive 3D representations — that achieves near-isotropic 0.8 Å 3D resolution even under extreme missing-wedge conditions. This makes it feasible to recover the internal structure of nanoparticles, nanowires, and confined phases from sparsely sampled or limited-angle datasets, as often required for beam-sensitive or geometrically constrained materials.