A coherent way to image dislocations

TL;DR

This paper demonstrates that coherent x-ray diffraction (CXRD) offers a novel, more precise method for detecting and analyzing dislocations within bulk materials, surpassing traditional electron microscopy and x-ray topography limitations.

Contribution

The study introduces CXRD as a new approach for imaging dislocations in bulk materials, providing enhanced accuracy and insight into dislocation core structures.

Findings

CXRD can detect single dislocation lines in bulk samples.

CXRD provides detailed information on dislocation core structures.

Compared to electron microscopy, CXRD offers higher resolution for bulk dislocation imaging.

Abstract

The use of coherent x-ray beams has been greatly developing for the past decades. They are now used by a wide scientific community to study biological materials, phase transitions in crystalline materials, soft matter, magnetism, strained structures, or nano-objects. Different kinds of measurements can be carried out: x-ray photon correlation spectroscopy allowing studying dynamics in soft and hard matter, and coherent diffraction imaging enabling to reconstruct the shape and strain of some objects by using methods such as holography or ptychography. In this article, we show that coherent x-ray diffraction (CXRD) brings a new insight in another scientific field: the detection of single phase defects in bulk materials. Extended phase objects such as dislocations embedded in the bulk are usually probed by electron microscopy or X-ray topography. However, electron microscopy is restricted to thin samples, and x-ray topography is resolution-limited. We show here that CXRD brings much more accurate information about dislocation lines (DLs) in bulk samples and opens a route for a better understanding of the fine structure of the core of bulk dislocations.