Bragg coherent diffraction imaging (BCDI) offers insights for nanoparticle synthesis
Understanding and controlling how the diffusion process works at the atomic scale is an important question in the synthesis of materials. For nanoparticles, the stability, size, structure, composition, and atomic ordering are all dependent on position inside the particle, and diffusion both affects all of these properties and is affected by them. A more thorough understanding of the mechanisms and effects of diffusion in nanocrystals will help to develop controlled synthesis methods to obtain the particular properties; however, conventional methods for studying diffusion in solids all have limitations.
Given the need for imaging techniques that are sensitive to slower dynamics and allow the diffusion behaviour in individual nanocrystals to be investigated at the atomic scale and in three dimensions (3D), a team of researchers used the strain sensitivity of Bragg coherent diffraction imaging (BCDI) to study the diffusion of iron into individual gold nanocrystals in situ at elevated temperatures. Their work was recently published in the New Journal of Physics.
Image, third of three figures: Reconstructed amplitude and phase images near the centre of the nanocrystals before and after iron deposition (1 pixel = 16.28 nm). The direction of the Q-vector, which is along the (11-1) direction, is shown by the arrow in the control phase images. See all here.