Reconstruction of three-dimensional strain field in an asymmetrical curved core-shell hetero-nanowire

TL;DR

This paper presents a novel electron diffraction-based method to reconstruct the 3D strain field in asymmetrical curved core-shell nanowires, enabling detailed strain mapping even in defect-rich and beam-sensitive materials.

Contribution

It introduces a comprehensive analysis technique that handles twinning defects and allows 3D strain reconstruction from low-dose, single-zone diffraction data.

Findings

Successfully mapped 3D strain distribution in curved nanowires

Demonstrated method's effectiveness on defect-rich and sensitive materials

Revealed hidden core-shell geometries through experimental and simulation comparison

Abstract

Crystal orientation and strain mapping of an individual curved and asymmetrical core-shell hetero-nanowire is performed based on transmission electron microscopy. It relies on a comprehensive analysis of scanning nanobeam electron diffraction data obtained for 1.3 nm electron probe size. The proposed approach handles also the problem of appearing twinning defects on diffraction patterns and allows for investigation of materials with high defect densities. On the basis of the experimental maps and their comparison to finite element simulations, a hidden core-shell geometry and full three-dimensional strain distribution within the curved core-shell nanowire are obtained. As effect, a low-dose quasi-tomography data using only single zone axis diffraction experiment is received. Our approach is applicable also for electron beam sensitive materials for which performing conventional tomography is a difficult task.