Insights into strain change of calcite by imaging defect-driven dissolution in the presence of Pb2+

The presence of microscopic strain can determine the macroscopic properties of crystalline structures. However, the capability of quantifying and imaging strain variations in particles undergoing chemical reactions remains limited. Here, we exploit the ability of three-dimensional (3D) Bragg Coherent Diffraction Imaging (BCDI) to capture changes in the 3D strain maps and morphology of individual calcite (calcium carbonate, CaCO 3 ) particles before and after dissolution in a lead-containing aqueous solution at pH 3.7. BCDI reconstructions show that calcite dissolution occurs preferentially at tensile-strained regions near macrosteps. This observation demonstrates that the local reactivity of calcite (i.e., as measured by the spatial distribution of its dissolution rate) is influenced by pre-existing strains for as-grown calcite nanocrystals. Additional studies will be required to develop a predictive understanding of the strain–reactivity relationship.