Confocal Microscope Alignment of Nanocrystals for Coherent Diffraction Imaging

Abstract

We have installed and tested an Olympus LEXT confocal microscope at the 34‐ID‐C beamline of the Advanced Photon Source (APS). The beamline is for Coherent X‐ray Diffraction (CXD) experiments in which a nanometre‐sized crystal is aligned inside a focussed X‐ray beam. The microscope was required for three‐dimensional (3D) sample alignment to get around sphere‐of‐confusion issues when locating Bragg peaks in reciprocal space. In this way, and by use of strategic sample preparations, we have succeeded in measuring six Bragg peaks from a single 200 nm gold crystal and obtained six projections of its internal displacement field. This enables the clear identification of stacking‐fault bands within the crystal. The confocal alignment method will allow a full determination of the strain tensor provided three or more Bragg reflections from the same crystal are found.