Revealing lattice distortions near the metal-oxide interface with multislice electron ptychography in Nb3Sn

Nb₃​Sn is regarded as a strong candidate for particle accelerator applications, largely due to its higher critical temperature and superheating field compared to niobium, which allow for more efficient performance in high magnetic field environments. However, its relatively short coherence length, approximately 3-4 nm, makes it more susceptible to crystal defects, which can compromise its superconducting properties. Understanding the lattice distortions near surface oxides and defects is thus essential for improving its performance in these systems.

In this work, we will implement multislice electron ptychography to address some of the limitations of traditional techniques. Many conventional methods lack the spatial and depth resolution required to capture fine structural details. Even though dark-field Scanning Transmission Electron Microscopy (STEM) provides high spatial resolution, it often struggles to differentiate between surface and bulk layers of the material. Multislice electron ptychography, on the other hand, offers not only high spatial resolution but also enhanced depth sensitivity, enabling us to observe distortions at both the surface and deeper within the crystal structure. This approach aims to provide critical insights into how defects and oxide layers impact the integrity of Nb_3​Sn.