Simultaneous Multi-Bragg Peak Coherent X-ray Diffraction Imaging

Florian Lauraux,Oleg Kovalenko,Marie-Ingrid Richard,Olivier Thomas,Stéphane Labat,Tao Zhou,Eugen Rabkin,Steven J Leake,Sarah Yehya,Tobias U Schülli,Thomas W Cornelius,Odile Robach,Jean-Sébastien Micha

doi:10.3390/cryst11030312

Abstract

The simultaneous measurement of two Bragg reflections by Bragg coherent X-ray diffraction is demonstrated on a twinned Au crystal, which was prepared by the solid-state dewetting of a 30 nm thin gold film on a sapphire substrate. The crystal was oriented on a goniometer so that two lattice planes fulfill the Bragg condition at the same time. The Au 111 and Au 200 Bragg peaks were measured simultaneously by scanning the energy of the incident X-ray beam and recording the diffraction patterns with two two-dimensional detectors. While the former Bragg reflection is not sensitive to the twin boundary, which is oriented parallel to the crystal–substrate interface, the latter reflection is only sensitive to one part of the crystal. The volume ratio between the two parts of the twinned crystal is about 1:9, which is also confirmed by Laue microdiffraction of the same crystal. The parallel measurement of multiple Bragg reflections is essential for future in situ and operando studies, which are so far limited to either a single Bragg reflection or several in series, to facilitate the precise monitoring of both the strain field and defects during the application of external stimuli.

Highlights

In the last two decades, coherent X-ray diffraction imaging (CDI), which facilitates the three-dimensional mapping of nanostructured samples, has experienced tremendous progress
The Bragg coherent diffraction imaging (BCDI) of six independent Bragg peaks on a single defect-free ZnO nanorod was demonstrated, rendering a spatial resolution of 40 nm [4]
Bragg reflections was applied to a twinned Au crystal

Summary

Introduction

In the last two decades, coherent X-ray diffraction imaging (CDI), which facilitates the three-dimensional mapping of nanostructured samples, has experienced tremendous progress. This lensless imaging technique retrieves the sample scattering function from coherent X-ray diffraction data using computational inversion algorithms to determine the phase of the scattered wave, which is not directly measured by a detector [1,2,3]. The reconstruction of GaN nanowires containing inversion domain boundaries was demonstrated recently by measuring five independent Bragg peaks of the same nanorod, rendering a precision of 1 pm in the displacement field and a spatial resolution of 10 nm [5].

Methods

Discussion

Conclusion