X-ray irradiation induced strain relaxation of dewetted Ni particles on modified Si substrate

Abstract

Bragg coherent diffraction imaging (BCDI) is a powerful and unique technique that provides both a nano-resolution 3D image of a single crystal and the lattice strain within that volume. However, the difficulty in reconstructing the electron density of highly strained crystals using conventional phase retrieval algorithms limits its use as an imaging tool in the materials science community. In this work, a sudden relaxation of [111] and [100] oriented dewetted Ni particles on [Figure presented]/[Figure presented](001) under exposure to [Figure presented] X-rays is observed. Meanwhile, a [111] oriented dewetted particle on Nb:[Figure presented](001) remains strained under the same focused X-ray beam. The supporting substrate plays a critical role in the particle strain field, and can be leveraged to obtain strain free particles for in situ or operando BCDI experiments. This study highlights the importance of understanding X-ray induced structural changes when using focused synchrotron X-ray beams.