Revealing nano-scale lattice distortions in implanted material with 3D Bragg ptychography

Peng Li (1) , Nicholas Phillips (2) , Steven Leake (3) , Marc Allain (1) , Felix Hofmann (2) , Virginie Chamard (1)

1 COMiX - Coherent Optical Microscopy and X-rays
2 Department of Engineering Science [Oxford]
3 ESRF - European Synchrotron Radiation Facility

Small ion-irradiation-induced defects can dramatically alter material properties and speed up degradation. Unfortunately, most of the defects irradiation creates are below the visibility limit of state-of-the-art microscopy. As such, our understanding of their impact is largely based on simulations with major unknowns. Here we present an x-ray crystalline microscopy approach, able to image with high sensitivity, nano-scale 3D resolution and extended field of view, the lattice strains and tilts in crystalline materials. Using this enhanced Bragg ptychography tool, we study the damage helium-ion-irradiation produces in tungsten, revealing a series of crystalline details in the 3D sample. Our results lead to the conclusions that few-atom-large ‘invisible’ defects are likely isotropic in orientation and homogeneously distributed. A partially defect-denuded region is observed close to a grain boundary. These findings open up exciting perspectives for the modelling of irradiation damage and the detailed analysis of crystalline properties in complex materials.

Mots clés: Imaging techniques; Materials for energy and catalysis; X-rays; Imaging techniques

Domaines: Matière Condensée [cond-mat]

Peng Li, Nicholas Phillips, Steven Leake, Marc Allain, Felix Hofmann, et al.. Revealing nano-scale lattice distortions in implanted material with 3D Bragg ptychography. Nature Communications, 2021, 12 (1), pp.7059. ⟨10.1038/s41467-021-27224-5⟩. ⟨hal-03465546⟩